complete, and enabled us to prove, from anatomical characters, that it is with the greatest propriety that the majority of naturalists have regarded the dog, the wolf, the fox, and the chacal, as forming different and distinct species.

The observations which we now offer can scarcely be regarded as devoid of interest; they were suggested by Mr Jobert, one of the editors of the Bulletin de Geologie. This naturalist having honestly said, that he knew of no characters by which the skeleton of the dog could be distinguished from that of the wolf and fox, we have endeavoured to answer the appeal thus made, and have accordingly undertaken the examination and comparison of the skeletons of these animals.

At

Our place of residence, unfortunately, has not allowed us to give to the investigation all the perfection it might receive. a distance from a great museum, which, from the mania for centralization which afflicts France, is to be found solely at Paris, we have not been able to procure those means of comparison which are indispensable. At all events, however, we have done our best to avail ourselves of the collections which have been formed by the Faculty of Sciences at Montpellier, the result of that ardent zeal which animates them in the promotion of anatomical science. When heads of different races of dogs are examined, and attentively compared with those of the wolf and fox, it may easily be observed that differences exist between them much more important than those which result from the relative size.* Thus, in comparing the heads of many kinds of the dog, and particularly those of the mastiff, the pointer, the spaniel, and the carlin, with that of the wolf, it is easily observed that the cavity of the cranium is much more developed in the former than in the latter. The distance between the two parietal protuberances is also much greater in the dog than in the wolf. But the difference in the size of the cavity of the cranium,

*

Many naturalists will hear, not perhaps without surprise, that even Linnæus, in the 12th edition of his Species, and Gmelin, in the 13th, distinguished the wolf, dog, and fox, by the following characters alone: tail straight or bent to the left, or downwards, of a uniform colour, or tipt with white hairs. We subjoin the very words of the great naturalist. Canis familiaris, caudá sinistrorsum recurvâ.—Canis lupus, caudá incurvatá—Canis vulpes, caudâ rectâ, apice albo-Linn. Species Mamm. Ed. 12. p. 58, 59.

which is so evident when we compare the dog and the wolf, is far from being equally so when we institute a comparison between the former and the fox. It is true, that in the last mentioned animal, the lateral and superior parts of the cranium formed by the parietal bones, are much more convex than the corresponding parts of the wolf; though this convexity is less, other proportions being the same, than in the higher races of dogs, especially in the most intelligent, as, for example, in the spaniel.

According to these facts, the different degrees of intelligence in carnivorous animals, as in others, would appear to depend on the larger or smaller capacity of the cranial cavity; and hence we need not be astonished to find that this capacity is smaller in the wolf, than in the dog and the fox.

The forehead is generally of a more protuberant shape in dogs than in the wolf and fox, in which indeed it is almost flat. So much is this the case, that in these latter a line drawn from the upper part of the forehead to the anterior extremity of the square bones of the nose, is nearly straight; whilst in dogs, on the contrary, the line is very decidedly curved, its greatest concavity being placed a little before the orbits.

There is also seen in the wolf a well marked depression in the middle of the frontal region. This depression is more strongly marked in some races of dogs, especially in those of inferior intelligence, as in the mastiff, which we have had such frequent occasion to mention. We have also to remark, that the lateral portions of the frontal region are distinguished in the dog by being much more prominent than in the wolf. The fox also exhibits this portion nearly quite flat. Its forehead is also proportionally flatter than that of the wolf, and it does not present that deep furrow at the junction of the crests which proceed from the posterior orbital apophysis of the frontal and forms the sagittal crest. This crest is besides proportionally less elevated and shorter, in the fox than in the wolf: and the same remark may be made in relation to the wolf and the different races of dogs.

The sagittal crest, which in the wolf is formed by the union of the two parietals and the crests proceeding from the posterior orbital apophyses of the frontal, which unite in advance of the

fronto parietal suture, is very largely developed in this animal. In those varieties of the dog, which, like the mastiff, approach near to the wolf, the sagittal crest is also developed, though not to the same extent.

Concerning the crests which arise or proceed from the posterior orbital apophyses of the frontal bone, they are not less distinctly seen in dogs, but then they are constantly rounded off. They do not unite till after they have passed the fronto-parietal suture; and it is worthy of remark, that no trace of this sagittal crest is to be found in dogs, which, like the spaniel, possess the highest degree of intelligence. It is flat, rather broad, and formed by the scarcely prominent edge of two ridges, which, proceeding from the posterior orbital apophyses of the frontal bone, run along the superior part of the parietal bones, and unite at the external occipital protuberance. In this truly intelligent race, the sagittal crest scarcely projects above the surface of the cranium, and has thus neither the same prominence nor the same development which is seen in the other varieties of the dog. It may be remarked in general, that all the crests, all the processes, and all the projecting laminæ, are much stronger in the wolf than in the dog and the fox. Hence it follows that the muscular attachments are much larger and stronger in the first than in the other two; and thus the wolf, which is much more voracious than the others, has, from this circumstance alone, better means of satisfying his appetite.

The sagittal crest projects likewise in the fox, but the crests which come from the posterior orbital apophyses of the frontal bone, constantly unite with it, at least in all the adult specimens which are under our observation, behind the fronto-parietal su

ture.

With regard to the occipito-parietal crest, it is usually less prominent in dogs than in the wolf, without excepting dogs of the largest size, as the mastiff. Almost no traces of it are seen in dogs which have the rounded cranium; and this difference is the more apparent when the wolf is compared with the more intelligent races of dogs; and hence it is a more distin

hing mark, as we proceed from the mastiff to the spaniel.

e line and the bony crest which run from the edge of the matic arch, and pass above the external auditory foramen,

are proportionally stronger and more prominent in the wolf than in the fox and the dog. As to the contraction of the cranium, which takes place behind the post-orbital apophyses of the frontal bone, it is proportionally much more distinct in the fox than in the wolf.

If we turn the crania of the dog, the wolf, and the fox upside down, and compare the transverse extent of the head, thus reversed, on a horizontal plane, this extent will be found much larger in the first of these animals than in the others. Thus we are not surprised to find the arch of the palate having a larger transverse diameter in the dog than in the wolf and fox. The basilary portion of the occipital bone, which is articulated with the posterior part of the sphenoidal bone, also exhibits a much larger quadrangular surface in the dog than in the wolf. The fox, in this particular, resembles the dog, and this gives to both these animals a larger capacity at the base of the cranium. Finally, and this character is sufficiently marked, the occipital protuberance forms a projection much more prominent, and quite otherwise developed, in the wolf than in either the dog or the fox.

The orbits of the fox are proportionably larger than those of the wolf. This is also true respecting the orbits of the dog, especially of the more intelligent races. The difference becomes more sensible as we proceed from the mastiff to the spaniel, or to any other variety which is highly domesticated. The snout of the fox is usually narrower, and more slender than that of the other animals with which we are now comparing it; so that it has almost become a proverb regarding individuals with a somewhat long, narrow, and projecting face, that they have a reynard's snout.

There are still other characters which help to distinguish the different species we are now considering; for example, the occipital foramen, which is almost circular in dogs, even in the mastiff, the variety most resembling the wolf, is, in this latter animal, of an oval form, the extremities of which answer to the inner portion of each condyle. Hence it follows that, in the wolf, the transverse breadth of the occipital foramen is greater than in the dog. In the fox also, this foramen has an oval shape, but the

transverse diameter is less, other proportions being the same than in the wolf; and thus the fox, in this particular, presents a kind of mean between the other two.

The form of the maxillary bones, and the arrangement of the teeth, likewise supply very good distinctive characters. Thus the intermaxillary portion which supports the superior incisors, usually appears larger in the different races of the dog than in the wolf; and, if this distinction is not so marked in the fox, it may at least be noticed, that in it the superior incisors are more widely separated from each other than they are either in the wolf or in any variety of the dog.

The canine teeth of the dog are thicker and shorter than those of the wolf and fox. The latter of these animals is particularly distinguished by having its canine teeth very long, very acute, and probably thinner than in the dog or wolf. Their length is such, that when the incisors are in contact, the superior canines descend lower than the level of the inferior maxillary, which corresponds to them; and, in the same way, the inferior canines, in ascending, mount up considerably above the level of the floor of the nasal fossæ; appearances which are not witnessed either in the wolf, or in any of the varieties of the dog. This distinction is the more striking, as the canines in the fox have a more decided curve than the same teeth in the dog and wolf. In the young fox, the milk canine teeth are furnished, at the base of their posterior aspect, with small tubercles, which are not to be found on the permanent teeth.

The molares of the fox also present some peculiarities. The false molares so exactly cross each other, that when they are approximated, the point of the superior corresponds to the junction of the anterior and posterior edge of two inferior teeth. Thus their points nearly fill the void spaces which separate the teeth from each other. In consequence of this arrangement, these teeth are, as it were, inserted into each other, an appearance which is not presented in the dog or the wolf. In this last, in fact, the point of the superior molares projects before and beyond the point or most elevated tubercle of the inferior false molares; so that, in consequence of the. oblique direction of the teeth of the upper jaw, there exists a considerable void space,