scaphocephali, the shape of the brain must necessarily have been so modified as to adapt it to the altered form of the cavity in which it was contained. In such cases, therefore, we cannot look upon the cranial bones as impassive in their influence on the cranial contents. Has, then, this change in the shape of the brain produced any diminution of or alteration in its functions? To this question it will not be easy to give in every case a very definite reply; for to many of the crania no history is attached. Virchow certainly says that the skull, (fig. 12, p. 906) belonged to an epileptic; and at p. 920 he states that in most of the groups of prematurely synostotic crania he has described, skulls of notorious Cretins, of insane persons, of epileptics, or of those who came from notorious Cretin-localities, may be found. Though on page 922 he admits that deformed synostotic crania do not necessarily co-exist with a disturbance of the mental activity. But although some of the individuals who possess scaphocephalic crania may have exhibited intellectual deficiencies, or a tendency to cerebral affections, yet it by no means follows that this shape of head is necessarily accompanied by such tendencies or deficiencies. Of the two children whose cases are recorded by Dr. Minchin the one is stated to be remarkably quick and intelligent, and not to exhibit any symptom of cerebral disease. The other never complained of his head, had no symptom of cerebral irritation, nor anything like brain-disease. He was good-humoured and playful, and by no means deficient in intelligence. The scaphocephalic skull which Lucæ figures in his plate 111, belonged to a man who possessed great erudition and powers of memory, and who had often very honourable duties entrusted him to discharge.* And, in addition, Lucæ states that he knows a boy with a well marked elongated head who possesses no mental peculiarity worthy of remark. The member of my own profession with a head of this form, to whom I have already alluded, was characterised as a student by great perseverance and industry, and possessed excellent abilities.†

The combined evidence of travellers in those parts of the world in which the process of forcible cranial compression is systematically pursued, goes to show that no disparity of intellect exists between

Zur Morphologie der Rassen-Schädel.' p. 53.

† Dr. Allen Thomson also tells me that he had at one time a student from the West Highlands in his Anatomical Class, whose head was of this form.

those whose heads have been so compressed and those who possess the normal shape of skull. The limit which has been placed to the growth of the skull and brain in certain directions being counterbalanced by increased growth in others. So in these cases nature herself by inducing a premature synostosis of adjacent cranial bones, puts a stop by this process of natural compression to the growth of skull and brain in a given direction, and at the same time, permits a compensatory increase to take place in others, and thus the cranial capacity, and in many cases the mental capacity also, are but little interfered with.

*

Scaphocephalic crania are not characteristic of any particular people or race. They have been met with in natives of Great Britain and Ireland, Germany, and Denmark. From a note which (by the kind permission of Mr. Flower the Conservator of the Hunterian Museum) Dr. James Pettigrew, the Assistant Conservator has favoured me with, I think it probable that a skull-cap in that collection, 5557, marked Gentoo, belongs to this form. In the Blumenbach Collection is a cranium marked Macrocephalus Asiaticus, which was presented to the distinguished Ethnologist by the Baron von Asche, who wrote that it was probably a Tartar. Blumenbach, from the name which he gave to it, was apparently of opinion that it corresponded in its shape to the Hippocratic Makrocephali, though, with learned caution, he hesitated, in the absence of any positive information regarding its immediate origin, in coming to any decided conclusion respecting it. Since he published a drawing of the skull, some ethnologists have supposed its peculiar shape to have been occasioned by compression. Dr. Minchin, however, from an inspection merely of the plate engraved in the 1st Decas of Blumenbach's great work, concluded that this head corresponded with those which he has described in his paper already so frequently referred to, and the peculiarities of which we have been discussing. This conclusion of Minchin's has now been satisfactorily confirmed by the venerable Von Baer, who has personally examined it and the other crania in the Göttingen Collection, and to whom we are also indebted for pointing out that the skull marked 'Danish' is of the same description.

Decas 1. Tab. 111. p. 17.

TABLE I.

In this paper, I have in a great measure restricted myself to a consideration of the effects produced on cranial forms by premature synostosis. But, in conclusion, I may state, that the opposite condition, viz., prolonged persistence of a suture, which normally closes early in life, exercises an effect upon cranial growth exactly contrary to that which is produced by the early ossification. And in support of this statement I may especially refer to those cases in which the frontal suture remains long open. In these cases, great comparative frontal breadth will be found to be an almost constant accompaniment. I have now examined a considerable number of crania in which the frontal suture exists; and from my observations on these specimens, it may safely be inferred that the persistent frontal suture and well-marked frontal breadth have certain relations to each other. The conjunction of hydrocephalus with an open condition of the sutures, and the production of that form of head distinguished as the hydrocephalic head, are so well known, that it is needless that I should do any more than merely allude to them on this occasion.

XIX.-ON SOME ANOMALIES IN ZOOLOGICAL AND BOTANICAL GEOGRAPHY. By Alfred R. Wallace, F.Z.S.

THE subject of Geographical Distribution is now generally allowed to be one of the most interesting branches of Natural History, and owing to the accumulation of much trustworthy material within the last few years, we are at length enabled to generalize many of the most important facts, and to form a tolerably accurate idea of the import and bearing of the whole inquiry.

In the admirable chapters on this subject in the "Origin of Species," Mr. Darwin has given us a theory as simple as it is comprehensive, and has besides gone into many of the details so fully as to render it needless to say another word here on those parts of the question which he has treated. As an explanation of the main facts and of many of the special difficulties of geographical distribution, those chapters are in every respect satisfactory; and I, therefore, propose now to consider only the anomalies and discrepancies which so frequently occur between the distribution of one class or order and another, and to discuss the possibility of arriving at a division of