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to be found, while in Darwinella, triaxon horny spicules means unlikely that the sponges may exclusively absabound.

liquid food—that is to say, organic substances dissaron Very interesting accounts are given of the connective in the water which is continuously passing through the tissue, muscle cells, and nervous system. Stewart's canal system. All the other organisms in which arazo account of the “palpocils” is accepted ; and, although ments are made to insure a continuous water cure Prof. Stewart's specimens are the only ones which show | I refer to the higher plants-absorb exclusively nouris these organs properly, yet Lendenfeld thinks that, when material in solution (the absorption of gaseous fore dhe groups

of converging sense-cells are observed (in sections) plants does not concern us here). The existence de below the continuous surface, these may be regarded as traversing canal system and a continuous water current the cells of a “retracted” palpocil.

seems to me to point to the nourishing material The researches of the author have thrown but little sponges being in solution in the sea-water. The numera fresh light on the subject of the occurrence of the strange fine sieves and filter arrangements generally, and the mere "filaments” in the species of the genus Hircinia ; these fact that the water always enters through the smaller how filaments are generally more abundant in the superficial and is expelled through the larger, clearly shows that a layer than in the interior of the sponge. They may be sponges are not desirous that large food-particles shocked isolated, or arranged in bundles of varying thickness, in enter their canal system.” which they are parallel. Such bundles are particularly Even granting that the word "exclusively" shouki te conspicuous in H. gigantea, where they form a pretty after the word “material,” we do not quite understai. uniform network which pervades the whole of the sponge. the comparison of the well-known facts of plant phyao' 7 The filaments are never straight : they may be continuously as they are presented to us in the above extract, nor di and simply curved, or they are undulating. The latter form | how it helps us to an understanding of how the pa of curvature is particularly frequently observed in the adds to its protoplasm ; the undoubted power possa filaments which are joined to form large bundles. While by some of the sponge-cells to lay down silica, lime,år : their abundance is subject to variation, no case of a quite different functionally from the phenomena attenere sponge with but a few isolated filaments is on record. No growth and development, using these terms in Herne apparent young stages of these filaments have been seen. Spencer's sense; but once set a thinking, our autan, Schulze's researches enabled him to make no positive proceeds, and telling us that a ta pe-worm is an anni statement concerning them, but they at the same time which takes up liquid food, and which has no sper demonstrated that no cellulose is contained in them, digestive apparatus, and that it evidently takes up a gred that they have no trace of true cellular structure, and quantity of material from the surrounding chyle throat' that they contain a great deal of nitrogen (9*2 per cent of the apparently indifferent cylindrical ectodermal epis, their substance), and that they are not Algæ. The resist- lium cells ; that the excess material and waste prod: * ance of the filaments in boiling alkali is against their are got rid of by the nephrydia,” he goes on lo se! being ordinary Fungi, while their general chemical com

that he is inclined "to think that in sponges we may have position indicates no relationship to the ordinary sponge a similar mode of absorption of nourishment; but that skeleton.” As to the very minute dumb-bell shaped struc- where are the nephrydia or their analogues? anca tures observed by Poléjaeff, and considered by him to be thinks again “that it is not impossible that the clined young stages of the filaments, Lendenfeld thinks that this chambers may be partly analogous to the nephryda de is extremely doubtful, “particularly as nobody besides the Cælomata, and that the collar-cells may, bes.sa Poléjaeff has seen them in H. friabilis or any other performing other functions, also secrete the urice sponge." But is this so? for in another paragraph we

However uncertain, he adds, this hypothesis may appear read :

“I think there can be no doubt that there is more prose * The spherical bodies which Schmidt and Poléjaeff bility in it than in the view, held by Carter and others ! consider as young stages of these filaments-in fact, as

the older authors, that the ciliated chambers are merely terminal knots, either dropped off, or on the way to pro- digestive apparatus." This seems a rather dreamy bito duce a filament-have also been observed and carefully thesis, with no facts for its foundation ; but it is but is studied by Schulze, who considers them as monocellular to remark that it comes at the very end of a volume wha Algæ, which have nothing whatever to do with the is a record of numerous and important observations filaments."

Under the headings variability, parasitism, and 50 Lendenfeld says that “no trace of filaments or ‘spores, biosis, many interesting details are given. The autem can be detected in the young embryos which are often thinks that certain forms of Aulena and Chalinopsi found in specimens of Hircinia.”

imitate certain siliciferous Cornacuspongix. Thr On the physiology of the group, this monograph throws sponges have descended from those which they imitus but little light :

and, whilst they have lost the spicules in the fibres, there “Our knowledge of the vital functions of sponges is at

have retained the outer appearance of their better prii present exceedingly unsatisfactory. We do not even tected ancestors in a most striking manner." Apparaty know which parts of the sponge absorb nourishment, “ the primordial sponge ancestors were free-swimmie or, in fact, what kind of food the sponges take in. We and had no skeleton. Some produced a calcareth are equally ignorant concerning their respiration and others a siliceous skeleton ; in both the subsequel secretion."

development, the formation of ciliated chambers, toti There being then no facts to serve us as guides to the ancestors did not possess, and the fixing of the 21 knowledge, the next “best thing ” is to have recourse to and rays of the spicules, were the same. The primer imaginations, and our author “thinks " that "it is by no Silicea had indifferent irregular spicules, from which the

wa and the tetraxon spicules were developed by an county, except in the extreme north and near the coast. wapuution of the divergent development of the canal The mixed lands are found--one portion east of the heavy tem. The primordial forms of both lived in water lands between the Orwell and the Stour; a second in the .. n silica, and certain forms of both lost their spicules north, between Halesworth and Yarmouth ; and a third Hercequence perhaps, of rising from deeper to shallower west of the heavy lands between Holston and New.. air, where silica is more scarce. In both, some forms market. The sandy, or light, soils are in the extreme

iust the skeleton altogether, while others have re- north-west, in what is called the “Breck district," between ed it gradually by spongin.”

Thetford, and Mildenhall, where are found the rarest Minule acknowledging that some authors whose opinions plants of the county, such as Veronica hybrida, V. tri1: carry great weight, such as Balfour, Bütschli, and phyllos, V. verna, and Apera interrupta. The coast is .:25, consider the sponges as a separate group, equal remarkable for the extent of its tidal estuaries and bays, calze to the groups Protozoa and Metazoa, Lendenfeld creeks and havens. There are no cliffs of any consider

ne but conclude that the sponges are, without doubt, able height, but a great extent of sand and shingle. The "-dija, and certainly Cælentera, in the sense of being beach at Orford, where grows the great mass of Lathyrus unded with a simple body cavity.

maritimus, the seeds of which saved the life of many The last twenty pages of the work are devoted to a poor people in a famine in the middle of the sixteenth kuopas of all the known sponges, giving the classes, century, is said to have the greatest breadth of sand any.

blies, onters, and genera. In this extremely useful list where on the English coast. The rivers are shallow Le!e is a short analysis of the families and orders, streams with slow currents. In the north-east there are nch is based on the labours of Vosmaer, Ridley, Dendy, several lakes of brackish water, not so well known as the soils, Schulze, added to those of the author's own. The Norfolk Broads, of which Braydon Water covers 1200, author ends his treatise with the statement that “Now and Thorpe Mere 1000, acres. The fresh-water lakes of : at all the groups of sponges have been thoroughly in- the county are few and small. There is a considerable instigated, we may consider our knowledge of their phylo- area of fen- and marsh-land, both in the north-west and mer tinities established on a satisfactory footing” east, so that we get in the county all the conditions that to ro'; but it seems well to call to mind the statement produce a rich low-country flora, and, superadded to the

sh thich he closes his short preface, and with which we common lowland plants, rarities characteristic of chalk lock the more inclined to agree, “our present knowledge country, the seashore, and fen-land ditches and marshes. **!30 Toup ... bas only just arrived at a stage corre- The country is so easy of access from the centres where

neing to the knowledge of the higher animals of half have lived many of the best botanists of bygone time, fertury ago" (p. 5).

such as London, Cambridge, Yarmouth, Norwich, and i a concluding our only too brief notice of this important Saffron Walden, that the principal features of its botany **th, for which all workers on the group must thank Dr. have long been known, and many excellent botanists, Lundenfeld, ve may mention that the sponge portraits from the time of Buddle down to the present day, have -"* for the most part photo-lithographs taken from the resided within its compass. The father of Suffolk botany emaal types; though in a few cases, where no good was Sir John Cullum, F.R.S., who lived near Bury St. -e mens were available, the lithographic illustrations Edmunds, and kept a diary between 1772 and 1785, in

which he has recorded the occurrence of upwards of 500 plants.

To his son, Sir Thomas Cullum, F.R.S., who was also an enthusiastic botanist, Sir J. E. Smith dedi

cated his “ English Flora.” In the present work there is THE FLORA OF SUFFOLK.

not only a full general history of the progress of Suffolk i Fiori of Suffolk. By W. M. Hind, LL.D., Rector botany, but, under each plant, the name of its first known o Honington, assisted by the late Churchill Babing- collector is registered. The first “ Flora” of the county wa, D.D., F.L.S. With a Chapter on the Geology, was published in 1860. It was carried out mainly by the mate, and Meteorology of Suffolk, by Wheelton exertions of the late Mr. E. Skepper, working under the

inud, M.2)., F.R.C.S. Pp. 508, with a Map. (Lon- superintendence of Prof. Henslow. After it was pubdon Gilbert and Jackson, 1889.)

lished, Mr. Skepper made a great many notes for a new IFFOLK is a characteristic lowland maritime Eng- edition, but he died in 1867. For several years the Rev.

lish rounty, the flora of which, at the present day, Churchill Babington, who settled in the county in 1866, Loans absolutely no infusion of the boreal element. paid attention to the subject. In 1875, the Rev. W. M.

ztea is about 1550 square miles. The whole surface Hind, a very competent botanist, well known by his • d.d., without any prominent rocks. It is underlain by “Flora of Harrow," settled in the county, and Dr.

stuk, which, in the north and west, lies immediately Babington sought and obtained his assistance to carry row the subsoil, but, in the south and east, is covered on the work. Dr. Babington died early in the present

Tertiary and Glacial deposits, which at Harwich have year. en found to reach a thickness of 1000 feet before the The bulk of the book is, of course, occupied by the codeck reached. In White's history of the county, its

enumeration of the species and an account of the dissit are classified into three groups: heavy lands, in

tribution and special localities of the varieties. The ebusch clay predoininates ; mixed land, common mixed county is divided into five districts, and the distribution

I nich deep moulds, fen-lands, and rich marshes; and of the plants is traced through them. Only the Phaneroini lands, consisting of sand over chalk. To the first gamia and Vascular Cryptogamia are dealt with, bu ** belong the soils of the western two-thirds of the the mosses of the county have also been well worked.

use trom drawings.

There is also a detailed tabular comparison of the plants process, and finally of Thomas and Gilchrist's bas of Suffolk with those of Norfolk, Cambridgeshire, and process. Essex, and a short chapter on the characteristic plants of The chapter which deals with chemical principles and the different soils of the county, which will be found very changes, inserted for the benefit of those having a limie. interesting to students of plant-dispersion. The chapters knowledge of chemistry, is valuable on account of the contributed by Dr. Wheeler Hind, the son of the editor, simple manner in which it is written ; this is particulars on the geology, physical geography, and meteorology of the case as regards oxidizing and reducing agents, the the county are very full, clear, and add greatly to the examples given of oxidation and reductior showing *Be interest of the book.

reactions very clearly. A chapter is devoted to the One of the most interesting circumstances in the county definition of metallurgical terms, refractory materials and flora is the occurrence of several maritime plants far fuel, another to the ores and alloys of iron, and then a inland. In the Breck country, between Thetford and description of the various processes employed in the metaMildenhall, grow Vicia lutea, Erythræn littoralis, Rumex lurgy of iron and steel is given, attention being preds maritimus, Carex arenaria, Phleum arenarium, and equally divided between the two metals. Corynephorus canescens. These are all seaside plants, The most ancient and most difficult method of er and their occurrence fifty miles inland is accounted for tracting iron from the cre is what is known as the direct by Prof. Newton and the editor by supposing that an arm method, and the author explains clearly the two causes of of the sea has penetrated here southward from the Wash its failure, whether in the case of the old Catalan or as at a comparatively recent period.

of the modern processes, and the reason why the blas It is in Norfolk and Suffolk that the most valuable furnace, although an indirect, has proved so successful : observations have been made, by Mr. Clement Reid and method. These two causes are "the easy oxidation of his fellow-workers, in illustration of the time of origin iron by carbonic acid and water, at the temperature x: of our present British flora. The Cromer plant-bed ex- which ferrous oxide is reduced to the metallic state bye tends into Suffolk, past Pakefield, to Southwold and Dun- carbon, carbonic oxide, or hydrogen, and the facility wie! wich. This is pre-glacial, and yet, out of upwards of forty which iron at a red heat combines with carbon." plants found in it that have been clearly identified, there The preparation of the ores for reduction in the blas are only two that are not British now—the spruce fir and furnace and their treatment therein are next brousa

Trapa natans. At Hoxne, near Diss, lacustrine deposits forward, the advantages and disadvantages of the bor have been found resting on a bed of boulder clay, but blast, the utilization of waste gases, the dimensions and beneath beds which contain bones of the elephant. In form of blast furnace and subsidiary subjects becs these are contained Salix polaris, S. Myrsinites, Betula treated of. nana, Hypnum sarmentosum, and a Pinus which is The metal being now in the state of pig-iron, the mead: probably sylvestris-all characteristic Arctic-Alpine types, of refining and puddling are described ; the various arassociated with many lowland plants which grow un- rangements are set forth by which attempts have been changed in Suffolk at the present time. A chapter in the made to effect the work of the puddler by mechaniča, book contains a list of all these plants, but their geological means, whether by automatic rabbles or rotatory furnaces

, position is not clearly explained.

and their relative advantages and disadvantages. A chap It will be seen that this is a very interesting and com- ter is devoted to the treatment of puddled iron unde plete county flora, and that it is worthy of being studied the hammer and in the rolling mill, and to the tinning carefully by all who are interested in the distribution of and galvanizing of iron. our indigenous plants.

J. G. B. Leaving the subject of malleable iron, the author ner

considers the question of iron-founding. He descrites THE MANUFACTURE OF IRON AND STEEL.

the cupola furnace in which the pig metal is fused ; and ezt

various methods of moulding and casting, and the brand: Iron and Steel Manufacture. By Arthur H. Hiorns. of pig-iron used for different purposes, are treated of. (London : Macmillan and Co., 1889.)

About a third of the book is devoted to the considera THIS "HIS volume is meant as a text-book for beginners, tion of steel ; it is in this branch of the treatment of imza

and will very worthily occupy that position. It is that the greatest development has occurred of late yeuri. full of information, and information of the very kind and the book under review treats of all the modern which the student should possess before entering upon practice. It is pleasant to find, too, in the preparation the study of the greater works of Percy or Fhillips. On an elementary work, that constructive perspective bas the other hand, those already engaged in the metallurgy been employed. Modern processes are not brought in of iron and steel will find in these pages much that may prominence simply because they are modern, and ancien be referred to.

methods are not thrown into the shade is still employau The book begins with a brief history of the processes Amongst the latter we find full attention given that have been employed down to our own time, the land- cementation process, and crucible steel ; whilst a chapet! marks in which are Dud Dudley's successful attempts to is devoted to each of the processes of Bessemer smelt with coal at the beginning of the seventeenth cen

Siemens. The book finishes with a chapter on steel tury; Cort's introduction of the puddling process in 1784 ; casting and on testing. Neilson's recommendation to use hot blast in 1828 ; the The volume before us is intended to assist pupii revolution produced in the iron trade by the invention preparing for the ordinary grade examinations of the of the Bessemer steel process in 1855, as suppleniented and Guilds of London Institute, and its authorby R. F. Mushet, of the Siemens furnace and steel principal of the School of Metallurgy in connection will

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the Birmingham and Midland Institute-is to be con- volume he sums up the impressions produced upon him gratulated on the good work he has done in this con. by what he saw and heard in the course of his voyage. nection. The book is illustrated with 72 figures, which agree

Mr. Moss, in dealing with matters which really interest

him, shows that he is an accurate observer and a man with the simplicity and clearness of the diction, and ques

of sound judgment. His style, although plain and ba-tiuns are found at the end of each chapter, which have

unpretending, is well fitted for the task he has fulfilled. b. been well prepared to test the learner's apprehension of The best parts of the book are those in which he tries to

La contents. We are pleased to be able to recommend convey some idea of the daily life led by those natives ti tius little work, as a foundation for the study of the

whose customs he had an opportunity of studying. He in metallurgy of iron and steel.

appreciates warmly some aspects of the various Polynesian types of character, but thinks that the people are likely to degenerate rapidly, unless they can be

provided with a better class of native teachers than most OUR BOOK SHELF.

of those to whom the duty of guiding them is now 1: On the Creation and Physical Structure of the Earth. I

intrusted. What is needed, he thinks, is, that the is. By 1. T. Harrison, F.G.S., M.Inst.C.E. (London:

landers shall have in their work and in their amusements Longinans, 1889.)

freer scope for the imaginative powers with which they

are endowed, and the exercise of which is too often TH!s book brings to mind one of the most winning of the foolishly discouraged. Everything Mr. Moss has to say tagines of childhood. A bright child of an inquiring on this subject deserves the serious consideration of those tim will sometimes sit with comical sedateness listening to whom his warnings and counsels are either directly or iu the talk of its elders. It may afterwards be overheard indirectly addressed. repeating to one of its playmates, or to some lucky adult who itas the knack of winning its confidence, such adetached scraps of the conversation as have found a

LETTERS TO THE EDITOR. re!1ng place in its little brain; and, conscious even at its curly age of the necessity of some continuity in a narra- [The Editor does not hold himself responsible for opinions exlive, filmg up the gaps with inventions or criticisms of its pressed by his correspondents. Neither can he undertake wn, charming every way, but mainly on account of their to return, or to correspond with the writers of, rejected viter want of connection with the subject of the conver

manuscripts intended for this or any other part of NATURE, at.on which it is attempting to report. So our author

No notice is taken of anonymous communications.) das istened to the teaching of many geologists, and has Who Discovered the Teeth in Ornithorhynchus ?

died many detached passages from their writings : these be repeats to the world in a book, printing between them

IN NATURE of November 14 (p. 31), Profs. Flower and Latter * No ments and lucubrations of his own, about as innocent

criticise my note which appeared the week previous (November and as little apposite as the child's prattle-hardly so

7, p. 11), concerning the discovery of teeth in the young Orni.

thorhynchus. They promptly dismiss my claim that Sir Everard aflusing, however. The following passage is a fair sample Home discovered the teeth of the young Ornithorhynchus, by of the writer's own share in the book. “The termination

stating that the structures described and figured by Sir Everard of the Secondary Period, which introduced these altered are the well-known cornules of the adult animal.

onditions of the surface of the northern hemisphere, was If they will take the trouble to turn to the plate cited by me really the commencement of what is called the Glacial namely, Plate lix, of the second volume of Home's “ Lectures,” educh in Europe. We have noted signs of glaciation 1814–and will read the accompanying explanation, they will see canng the deposition of the upper chalk in India and that Home was familiar with the teeth of both the young and the arih America, but now the conditions which induced that

old animal. Bariation are extended in such a manner as to unite

For the benefit of those who may not have access to Home's Shese districes, and produce that enormous accumulation

Lectures," I here reproduce outline tracings of two of his of stiuw and ice at the North Pole, the weight of which in

figures. Plate lix. Fig. 2, shows the teeth of the young Orni

thorhynchus--the “first set,” as Home says, to show that the Mocne epoch depressed the crust in that region

there are two grinding teeth on each side.” The next figure is and upheaved the mighty mountain ranges to which I a similar tracing from the succeeding plate in Home's “ Lectures baie just referred."

I (Plate 1x.), which represents, to again use Home's words, “the The book bristles with cataclysms and catastrophes. under jaw of the full-grown Ornithorhynchus paradoxus, to The shifting of a thin crust on an internal nucleus which show that there is only one grinder on each side.” Both of 11 dnes not fit, and incessant protrusions of granite, are these figures are natural size. urokes to account for phenomena which every-day

In the face of these facts, further comment seems unnecessary people still persist in thinking are satisfactorily explained

I admit, of course, that Iome did not discover the chemical by every-day causes. But the author is one born out i composition of the teeth of the young animal—this was Poulton's of due time-iwo centuries too late. How he and Burnet discovery.

C. HART MERRIAM. would have enjoyed a crack together! But there is this

Washington, D.C., November 30. iu be said, the "Sacred Theory of the Earth” is Burnet's

[We do not reproduce the outlines sent, as anyone interested mt: the staple of the present work consists of extracts in the subject may see the originals, not only in Home's "Comfrom the works of others. The mottoes are verses from parative Anatomy,” but in the Philosophical Transactions, where she dirst chapter of Genesis, but their relevancy to the they first appeared. -- ED. NATURE.] szinject-malier of the chapters which they head is not

A. H. G. I SHOULD be very sorry to deny the credit of any discovery

to Sir Everard Home, or anyone else, if any evidence could Zrough dulls and Islands in the Great South Sea. be shown of its having been made. Of the figures cited by Dr.

By F. J. Moss. London : Sampson Low, 1889.) Hart Merriam, that of the younger animal seems (as far as can be Da Moss-a member of the House of Representatives,

judged from the roughly executed engraving, with the assistance Siw Zealand-started from Auckland, in September 1886,

of the descriptive text) to represent the horny plates, showing

the hollows from which the true teeth have recently fallen ; that in the schooner Buster, for a voyage among the islands of the old specimen, the same plates after they are fully grown, ind islets of "the outer lagoon world." He was absent

and their surfaces worn down by attrition. This difference led iteven months, and during that period he crossed the Home to conjecture that these plates were changed during the Culator six times, and visited more than forty islands growih of the animal--a view which was corrected by Owen sinong the least frequented groups. In the present *** Comp. Anat, of Vertebrates," vol. iii. p. 272), by the statement

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that "each division or tubercle of the shorny] molar is separately therefore, a considerable probability that in the living ari developed, and they become confluent in the course of growth.” the pigment is also soluble in water, I believe that this ye's a By the way, no one can have been better acquainted with the pigment is undescribed, but I have not yet completed my so work of Home than his successor in the Hunterian Chair, Sir of it; in any case, it is not zoofulvin or picisulvin, or Richard Owen ; and yet, in his numerous reserences to this "lipochrome."

FRANK E. BEDDAREN subject (Art. “Monotremata," “Cyclop. Anat, and Physiology”; “Odontography”; “Comp. Anat. of Vertebrates," &c.),

Exact Thermometry. no trace is shown of any knowledge of a discovery which could not have failed to have interested him, if it had been made IN the account which Prof. Mills has given (NATUKE, De before bis time.

ber 5, p. 100) of M. Guillaume's “ Traite pratique de la Thet If a cursory perusal of Sir Everard Home's first account of métrie de précision,” the permanent ascent of the zero-point of the mouth of the Ornithorhynchus (in the Philosophical Trans- a mercurial thermometer, after prolonged healing to a high actions for 1800), or any interpretation placed upon his figures, perature, is stated to be due to compression of the bulb-render: might lead anyone to infer, with Dr. Merriam, that the real more plastic by the high temperature-by the external atur teeth of the young animal had been discovered at that time, spheric pressure. the best possible authority may be conclusively cited against The constant slow rise of the zero-point of a thermomee! such an idea, no other than that of Home himself, who, in his the ordinary temperature is mentioned by Prof. Mills; and later description of the same specimen (“Lectures on Compara- late Dr. Joule's observation of this change in a thermor: tive Anatomy,” 1814), describes the organs in question as "the during twenty-seven years is specially alluded to.

It ; first set of cuticular teeth—an expression quite incompatible with imagine, be taken for granted that after the lapse of a sute their being the teeth described by Mr. Poulton and Mr. Oldheld length of time-possibly many centuries—a final state or eqr Thomas. It really seems superfluous to have to remind a brium would be attained ; and it has always appeared to e zoologist of such high repute as Dr. Hart Merriam that the that the effect of heating the thermometer to a high temperat me difference between teeth with the structure and mode of growth is simply to increase the rate at which this final state which characterize these organs in the Mammalia generally, approached. It is my impression that, owing to the more rát. and the horny epithelial plates of Ornithorhynchus, is not merely cooling of the outer parts of the bulb after it has been livsi, one of “chemical composition.”

W. H. FLOWER. the inner parts are in a state of tension, as, to a very exaggerare

degree, in the Prince Rupert's drops; and that it is the gracia

equalization of the tension throughout the glass that causoth The Pigment of the Touraco and the Tree Porcupine. contraction ; in other words, that the process is one of viso

annealing ATTENTION has been lately again directed to the red pigment

This explanation appears to be supported by the facts-'! in the wing feathers of the touraco, which has been stated by

that when a thermometer is exposed for a long time to al several observers to be soluble in pure water. Prof. Church,

temperature, the zero-point rises rapidly at first, then mwe who was the first to experiment upon this pigment (The Student,

more slowly, and finally becomes constant or nearly 50 ; (?:D vol. i., 1868 ; Phil. Trans., 1869), quotes Mr. Tegetmeier and

the higher the temperature the more rapidly is this stare a others, to the effect that this pigment can be washed out of the

equilibrium attained. I do not know of any experine : feathers by water. Later, M. Verreaux (Proc. Zool. Soc., 1871)

evidence that the rate of ascent is influenced by changes confirmed these statements from his own experiments while

external pressure, and it seemed to be desirable to tesi di travelling in South Africa ; attempting to catch one of these birds

point. whose feathers were sodden with rain, he found that the colour

In order to do this I have exposed three thermometers, 4.B stained his hands “blood-red.” A few years ago Prof. Kruken

and C, constructed by the same maker and of the same konice berg (“ Vergl. Phys. Studien ") took up the study of turacin—as

glass, to a temperature of about 28oo for several days in the s20 Prof. Church termed the pigment--and added some details of importance to Prof. Church's account ; Krukenberg, however,

vapour-bath, under the following conditions:-The the:D"

meters were all placed in glass tubes closed at the bottom. IL contradicted certain of the statements quoted by Church with reference to the solubility of turacin in pure water, remarking vapour of boiling bromonaphthalene. One of the tulies

being suspended from above), and the tubes were heated by a that the pigment in the dead bird is insoluble in water. A

containing thermonieter C-was exhausted so as to reduce the writer in the Standard of October 17 is able "partially to confirm ” the assertion that turacin is soluble in pure water. Seeing the air.

external pressure on the bulb to zero ; the others were open to

In thermometer A there was a vacuum over the that there is some conflict of opinion with regard to this matter, I think it worth while to state that I found it quite easy to ex

mercury, but air was admitted into B and C to increase the

internal pressure. Consequently, the bulb of A was exposed? tract with tap water (warm) some of the pigment from a spirit

a resultant external pressure equal to the difference between ite preserved specimen of the bird ; only a very small amount couid be extracted in this way, and the feathers were not perceptibly

barometric pressure and that of the column of mercury in it: decolorized even after remaining in the water for a fortnight. I

stem of the thermometer ; the internal and external pressurer ve

the bulb of B were approximately equal; lastly, ihe internet also experimented upon a feather just shed from one of the speci

pressure on the bulb of C was the sum of the pressures of the mens now in the Zoological Society's Gardens ; this was steeped

column of mercury in the stem and of the air above it, while tha in water for some time without any effect being visible, but after

external pressure was zero. a period of two days the water became stained a very saint pink.

The following results were obtained :The touraco, however, is not a unique instance of a terrestrial animal with an external colouring matter soluble in water. I

Zero before heating ... 0*15 am not aware whether other cases have been recorded, but I find a pigment of a similar kind in a South American tree porcupine

0'35 0 25 After 2 hours' heating

0:50 (Sphingurus villosus).

0:35 0*30

0.80 This porcupine has bright yellow spines which are for the

075 most part concealed by abundant long hair. The spines them.

After an additional 54 hours'
heating

1*30
selves are parti-coloured, the greater part being linged with a
vivid yellow ; the tip is blackish-brown. I was unable to extract

Total rise of zero-point... this pigment with chloroform, or with absolute alcohol even

I'15 when heated ; like so many other colouring substances which are The thermometers were heated until 5 p.m. each day, and insoluble in these fluids, the pigment could be extracted by the zero-points read on the following morning. potash or ammonia ; I found also that tap water, warm or cold, If the diminution of volume of the thermometer bulis, uszz't dissolved out the yellow colour ; the action was slower than observed, were due to external pressure, the zero point of A when the water was first rendered alkaline by the addition of should have risen, that of B should have remained 10:01 ammonia

, but, unlike the touraco, the pigment was nearly, if stationary, while that of C should have fallen. Instead out las. not quite, as completely dissolved. The skin, from which the however, the zero points of all three thermometers rose at niesi spines were taken, was a dried skin of an animal recently living the same rate; therefore the yielding of the bulbs to pred in the Zoological Society's Gardens; it had not been preserved owing to the plasticity of the glass, if it occurred at all

, had to in alcohol or treated in any way which might lead to the sup- sensible effect on the result.

SYDxEY YOUR position that the pigment was chemically altered. There is, University College, Bristol, December 12.

А

Rise.

C Rae

B. Rise.
ΟΙΟ - 010

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