fronto-sphenoid, parieto-sphenoid, malar-sphenoid and squamoso-sphenoid sutures all open. The squamoso-parietal sutures open anteriorly but quite obliterated in their posterior parts, and this obliteration extended along the parieto-mastoid and occipito-mastoid sutures, and also along the lambdoidal in the lower half of its extent, the union of the bones being so complete that there was no mark to indicate that any sutural line of separation had ever existed; thus the bi-parietal bone was continuous with the occipital and temporals. Frontal bone,

rounded and dome-like, projecting somewhat over the face, which looked small and narrow beneath the forehead. The rounded superior outline of the frontal bone was especially distinct in the anterior or frontal view. Superciliary ridges but faintly marked. A slight transverse constriction immediately behind the coronal suture. Skull laterally compressed in the parietal region, the eminences in which were absent. Squamous part of the occipital bone almost vertical, but below the curved line the bone passed almost horizontally forwards, so that the two divisions of the bone formed nearly a right

For permission to describe and give a figure of this cranium, I have to express my thanks to the Board of Curators of the Royal College of Surgeons, Edinburgh.

N. H. R.-1864.

H

angle with each other. External occipital protuberance well marked. Basi-occipito-sphenoid synchondrosis closed. No history of the

skull is given in the Catalogue.

III.-Skull-cap in the Anatomical Museum, University of Edinburgh. No. 117. No history of the specimen. Peculiarly elongated and laterally compressed. Sagittal suture obliterated; a well marked ridge extended along its line, and was prolonged downwards for some distance into the frontal region. The presence of this ridge and the lateral compression of the frontal and parietal bones on each side, gave to the skull-cap a characteristic keel-like aspect. A long and broad beak extended from the bi-parietal bone forwards into the frontal region. Two parietal foramina existed. A groove for the superior longitudinal sinus internally corresponded to the sagittal ridge externally. The coronal and lambdoidal sutures were indicated externally, but obliterated internally; but this obliteration was apparently the result of age. Frontal eminences

strongly marked. Parietal eminences absent. Skull laterally compressed in the parietal region, this character, together with the breadth in the frontal region, and the narrowed pointed shape of the occiput, gave to the calvarium a boat-shaped appearance, which was still further increased by the keel-like sagittal ridge. This ridge formed a prominent character in the anterior or frontal view of the skull-cap.

IV.- Cast, in the Museum of the Phrenological Society, Edinburgh. No. 25. The cast is stated to have been taken from a girl's

skull in the Spurzheim Collection. Although the cast is not a very finely marked one, so that it is not possible to state absolutely what the condition of all the sutures may have been in the skull, yet the sagittal suture is evidently obliterated. The elongation of the cranium, the absence of parietal eminences, the presence of a ridge along the sagittal line, the projecting occiput, the forehead somewhat overhanging the face, all indicate that the skull belongs to this group of abnormally elongated crania. An outline figure of this cast is given in Combe's System of Phrenology, vol. i. p. 417.*

The whole of these crania agree in possessing the following characters::

1st. Absence of a sagittal suture, and consequent blending of the two parietal bones.

2nd. Absence of parietal eminences.

3rd. Lateral compression.

4th. Great elongation.

In addition to these general characters, some of the specimens possess individual or special characters, which are deserving of notice. Of the general characters above enumerated, the one which primarily deserves our attention is the absence of a sagittal suture, for it is on this that the peculiar shape of the head, in a great measure, depends. First, we will inquire into the probable period of life at which it disappeared. Did it take place before or shortly after birth, or was it the result of age? I am of opinion that its disappearance occurred at an early period of life. For none of the crania, except perhaps the skull-cap, possessed any of the appearances of age. The skull in the Museum of the Edinburgh College of Surgeons and the cast in the Collection of the Phrenological Society, are undoubtedly those of young persons, whilst that in the Edinburgh Museum was from a man evidently in the prime of life, probably not

Since reading this paper I have, through the kindness of Professor Allen Thomson, had the opportunity of examining a fine specimen of an adult scaphocephalic cranium in the Burns' Collection in his possession in the University of Glasgow. The elongation, great lateral compression in the parietal region and occipital bulging are all well marked. But the skull is especially characterized by the squareness of the forehead, which gives to the face a massive aspect in its upper part. The sagittal ridge is prominent in the middle of the parietal region. Only one parietal foramen, and that on the left side of the middle line, is present. The denticulations of the coronal suture are very irregular, and but a faintly-marked beak extends from the bi-parietal into the frontal bone. The vertical transverse, and lateral lines of sutures are all unossified. Greatest length, 8 inches. Frontal breadth 4.6. Parietal breadth on level of squamous suture, 4 6. Horizontal circumference, 21 inches.

more than 40. But an example of a similarly formed cranium has been recorded by Dr. Minchin,* which furnishes us with still more positive testimony. He obtained it from the person of a boy, Daniel B., aged 3 years. The cranium possessed the characteristic elongated form. The sagittal suture was completely absent, and its line was indicated by a smooth osseous ridge, or elevation, extending from the lambdoidal apex to the middle of the coronal suture. Corroborative testimony has also been afforded by cases observed during life. A boy, John W., aged 9, had been for four years under the observation of Dr. Minchin; his head was greatly elongated and laterally compressed, and there could be no doubt that it belonged to the group of heads we are now considering. "From the time of birth the shape of his head "was a puzzle, and subject of pleasantry to his neighbours." The gentleman I have already referred to, personally known to myself, as possessing this form of head, is said to have had it from early childhood; and I am informed, by my friend, Dr. Dyce Duckworth, that he has had, for many years under observation, a boy, who, from infancy, had a head of a remarkably elongated shape, with its sides compressed, and with a high-domed forehead.

If then we accept the view that the absence of a sagittal suture and the existence of a bi-parietal bone date from a very early period, to what circumstance are we to ascribe this mal-development?

Two theories have been advanced by way of explanation. The first, originally proposed by Dr. Minchin and adopted by Von Baer, ascribes the malformation to the development of the bi-parietal bone from a single mesial centre, situated at the vertex, so that, according to their view, no sagittal suture had ever existed. The second, more especially advocated by Virchow, with which I am disposed to concur, regards the parietal bones as developed in the usual way, each from its own centre, but that, at a very early period, they coalesced along the sagittal line, so as to form but a single bone.

The arguments by which the theory of a single vertical ossific centre is supported are based upon the absence of parietal eminences, the presence of a ridge along the sagittal line, the projection of a beak forwards into the frontal bone, and the existence of lines radiating from the vertex.

The absence of parietal eminences is certainly one of the most constant characters exhibited by these crania, but it by no means

* Op. cit.

follows that such a condition is always and necessarily co-existent with an obliterated sagittal suture. For, as Welcker has pointed out (p. 117), they are occasionally absent in crania possessing an open sagittal suture, and which, without doubt, had tuberosities in early life.

The sagittal ridge, again, is not a constant occurrence in these crania. It is certainly well-marked in most of the specimens which have been recorded. It may be clearly seen in the University Museum adult skull, the skull-cap and cast described in this communication, also in the skull marked Fig. 13 by Virchow,* in the two skulls in the Blumenbach Collection,† in the cranium of Daniel B. figured by Minchin, in the Halle skull figured by Welcker, and in a skull (5732) and skull-cap (5732, a) in the Museum of the Royal College of Surgeons of England. But it does not exist in the youth's skull, No. 27, in the Museum of the Edinburgh College of Surgeons, and no mention is made of it in the description of the skull (Fig. 12) by Virchow (p. 906). Moreover, a ridge-like, keel-like, or roof-shaped summit is not unfrequently seen in many crania in which the sagittal suture is quite open, and in some races, as the Esquimaux and Australian, it appears to constitute an ethnical characteristic. And in many mammalia, as the orang, pig, and various carnivora, a sagittal ridge co-exists with a distinct centre of ossification for each parietal bone.

The existence of a beak projecting into the frontal bone has been regarded by Von Baer as important in its bearings on this single centre theory. It certainly is more or less strongly marked in the greater number of the crania which have been figured, and it is especially distinct in both the skull and skull-cap in the Edinburgh University Anatomical Museum. But it again, although a general is not a constant occurrence, for it is altogether absent in the youth's skull, No. 27, in the Collection of the Edinburgh College of Surgeons. I am the rather inclined to look upon this beak as indicative of a premature synostosis of two originally separate bones. It bears out what I have already stated in a former part of this paper, that the rate of ossific formation in one region of the skull may preponderate over

'Gesamm. Abhand.' p. 907.

† See Von Baer, 'Die Makrokephalen,' etc. Taf. iii. and Blumenbach, Decas, i. p. 17, Tab. iii.

The skull figured by Lucæ, Zur Architectur des Menschenschädels,' Taf. iii. (L. a. 227), does not appear from the drawing to possess a sagittal ridge, but in his later work, Zur Morphologie,' etc. p. 52, he states that the keel is strongly marked in it.