spores. Whether examined in water, spirit, or glycerine, the results are the same; but in nitric acid the threads are at first more distinct, but gradually become absorbed into an indistinct mass. When the film is stained with aniline or roseine, the threads and spores are brightly coloured by the medium, so that the details may be better observed. There is, however, still considerable difficulty in penetrating the film with a high power, and the threads will not separate.

*

From an examination of this fungus, with a view to the determination of its scientific relationship, we have come to the conclusion that it has no very close affinities, that it is not only specifically new, but will have to be accepted as the type of a new genus." Whether it is in itself an autonomous species, or a condition of some other and higher form, cannot be determined from present information; at any rate, it is so far complete as to possess a vegetative and reproductive system. The globose echinulate bodies have all the characteristics of spores, but more than this cannot be affirmed until some one is fortunate enough to observe their germination, or all endeavours to do so should fail.

The principal scientific question which presents itself in relation to this fungus is its relationship and affinity. Two or three suggestions have already been offered on the subject; although made without any microscopical examination of the plant itself, they are worthy of a passing notice. One suggestion is that the supposed fungus may be an imperfect condition of some lichen. It may be true that low forms, or imperfect states, of lichens are sometimes found on the living leaves of growing plants, yet the structure is hardly such as those lichenoid bodies. assume. Considerable emphasis is sometimes placed on the presence of gonidia in the lichen thallus as distinguishing it from fungi. There is no manifestation of such bodies in the present instance, and it would be more satisfactory for such an objection if a similar authentic instance could be adduced of a destructive leaf-parasite which is an undoubted lichen. Another suggestion has been offered that it may be a low form of Hymenomycetous fungi. If so, it should at least give some indication of its relationship. As spores are undoubtedly present, there should also be basidia, bearing these spores in pairs or quaternate; at least, there should be some evidence of an approach to such low hymenomycetal forms as Exobasidium or Hymenula. Probably it was some such organism as Exobasidium which was thought of when this suggestion was made, but, certainly, we can observe no relationship whatever between them.

"Pellicularia Koleroga "-Cooke in Grevillea, iv. p. 116. "On the Affinities of Pellicularia," in Grevillea, iv. p. 134. "Report on Diseased Leaves of Coffee and other Plants."

Apropos of the suggestion which has been offered through the medium of a horticultural newspaper, that the “black rot” appears to be the mycelium of some fungus, it will be sufficient to remark that the term "mycelium" is, by general consent, confined to productions which consist of barren threads. The presence of spores, in this instance, clearly removes the production beyond the limits of the term "mycelium." Unless terms are employed with their recognized meaning and limitations, some explanation should accompany their use to prevent misconception.

The conclusion at which we have arrived appears to us the most tenable one, that the fungus in question belongs to the Hyphomycetes, or moulds. In habit and external appearance it strongly reminds one of the white mould which precedes many species of Erysiphe, such as the one so common on peas in the autumn, or that which precedes Uncinula on the leaves of the maple. Even under the microscope there seems to be some kind of relationship; the interwoven, septate, colourless branched threads are present, but there is an addition of a somewhat gelatinous medium, which binds the threads together into a pellicle. The spores and their mode of production are different, and this, in the Hyphomycetes, is a most important distinction. In Oidium the spores are produced in chains, in the present species singly. It is very true that the structure, as seen in a drawing, resembles closely that of some species of Zygodesmus, but there is a peculiarity in the threads of many of the species in that genus that the threads are cut, as it were, nearly through at short distances, or abruptly bent, of which there is not the slightest indication here. The spores are very similar in size and form, but there are two or three features which appear to us conclusive for rejecting the coffee rot from this genus. In all the species of Zygodesmus the threads are. free from any investing medium, the spores are pulverulent, and, moreover, the threads are more or less coloured. Further than this, all the species occur on dead wood or leaves, and in no instance is a species parasitic on living leaves. Although too much reliance is not to be placed on this fact, it is nevertheless noteworthy that in genera in which the species are parasitic on living plants there is seldom an exception to this rule, and so in genera which contain species found on dead substances parasitic species are not found. In illustration of the former we may cite Peronospora, Ramularia, and Erysiphe, and of the latter Dactylium, Sporotrichum, and Zygodesmus.

The presence of the gelatinous element which binds together the threads and spores into a thin pellicle, which is easily separable from the matrix when moist, is an important feature in determining the affinities of the "coffee rot." In the genus

Amphiblistrum of Corda there is said to be such a gelatinous medium. In many species of Fusisporium there is something of the same kind; in Alytosporium as constituted by Link, and in some other genera allied to Sporotrichum. Still, from all these there are such manifest points of divergence that no one would venture to associate the present species with any of them. Hence no other course appeared to be open to us but to constitute Pellicularia Koleroga the type of a new genus, allied to those just alluded to, but distinguished therefrom by its parasitic habit, sessile, echinulate, globose spores, and the freedom with which it separates from the matrix. Whether

or not mycologists will accept this as a sufficient distinction, the present course has not been adopted without much consideration.

The fact of an epiphytal fungus, which does not penetrate the tissues of the leaf, being so destructive to the foster plant, may at first seem strange, until it is remembered that in plants with coriaceous leaves all, or nearly all, the stomata are confined to the under surface of the leaf. If, therefore, a filmy substance like the present fungus overspreads the under surface of the leaf, and securely seals up all the stomata, it is but reasonable to expect, not only that the leaves should fall, but that the plants should suffer injury. In such diseases as that which affects the hop, and which is but too well known to hopgrowers in this country, the chief destructive action lies in the closing up of the orifices of the leaf by the woolly coating of mycelium produced by the fungus.

From the similarity of habit and growth in the coffee rot to that of the hop mould, and, we may also add, of the vine mildew, it is extremely probable that the remedies which have been applied in the latter instances with success would be more or less advantageous in the former. It is now generally admitted that the application of the flowers of sulphur, by dusting over the leaves, is the most effectual remedy yet discovered for hop mould and vine mildew. It should certainly have a fair trial also in the case of the "coffee rot," and the presumption is strongly in its favour.

We have stated sufficient to show that the coffee plant in Mysore and in Ceylon is exposed to considerable danger from the two persistent enemies above described. Some plants of the Liberian variety were sent out some time since in the hope that its apparently stronger constitution would prove impregnable to the Hemileia. At first they progressed favourably, but subsequent information dispelled the hope, for the coffee disease had attacked them also. Unless some remedy is discovered there is reason to fear that even if the cultivation of coffee is continued in these places it will be unremunerative, or,

the costs and risks of the venture being so much increased, a corresponding increase in price will be a natural result. We have the experience of the vine and potato diseases, and more recently of the hollyhock disease, to warn us how surely and speedily the area of infection is extended, and though for the present some coffee-producing countries are free, one or other of the pests may at any time make its appearance where it has never been known before.

DESCRIPTION OF PLATE CXXXV.

a. Portion of leaf affected with "black rot."

b. Fragment of pellicle formed by the fungus Pellicularia koleroga × 500 diam., showing threads and spores.

c. Small portion of thread further magnified, with young and mature

spore.

d. Portion of leaf affected with Hemileia vastatrix.

e. Tufts of spores as they appear clustered on the spots, slightly magnified.

f. Young threads and spores x 500 diam.

g.

Mature spores of Hemileia vastatrix × 500 diam.

h. Globose bodies, or warts, from the surface of mature spores of Hemileia x 500 diam.

AMONG GLACIERS RECENT AND EXTINCT.

BY THE REV. W. S. SYMONDS, F.G.S.

IF

F we would see King Frost on his throne, we must travel to the Arctic or Antarctic regions. Of the latter little is known, save that there are mountains rising to the height of 15,000 feet, that the Antarctic continent is at present ice-bound and going through a glacial epoch, and that ships are stopped by pack-ice before reaching the 70th degree of latitude. Victoria Land, which extends from 71° to 79° south latitude, was ascertained by the exploring expedition of Sir James Ross (1841) to be fringed by an enormous barrier of ice; while the inland country rises from 4,000 to 15,000 feet above the sea, as in Mount Melbourne, and the crater of Mount Erebus is elevated to the height of 12,000 feet. Graham's and Enderby's Lands, in the Antarctic regions (lat. 64° and 68° S.), are situated in the same parallels of latitude as are those regions of the northern hemisphere which are inhabited by man and herds of wild animals; but the Antarctic lands are not known to possess a single land animal, and are wild, wintry, and desolate in the extreme. Frost reigns everywhere! In the Arctic regions of the distant North voyagers have explored much the seas and border lands-the home of Arctic men, and the abode of the musk ox, the polar bear, the walrus, and the reindeer.

The accounts of Greenland are remarkable. Some travellers. who have penetrated a few miles into the interior of southern Greenland describe it as occupied by one vast glacier, and state that in 70° N. the land of the interior is covered by one vast ice-sheet of unknown depth, which conceals and obliterates all indications of hill and valley. This vast mass of inland ice is in constant motion, creeping and advancing slowly, but with different velocity, in different places towards the sea. Near the sea it presents "ice-walls" rising sometimes to the height of 3,000 feet, and from these break off the iceberg and icefloe, with a crashing and then a roar like the discharge of a park of artillery. Some of the bergs ground in the fiords and break up slowly, others sail off to the ocean, sometimes rising to the