292 
DE. CLELAOT) ON THE EELATIONS 
men, in which I carefully disarticulated a palate-bone with an orbital process of that 
description, I found that that process had the whole sphenoidal spongy bone in union 
with it*. 
It will be seen from this description that the sphenoidal spongy bone forms an arch 
of communication between the ethmoid and exactly that part of the vomer from which 
in other mammals the ethmovomerine lamina springs. Also it is it, and not the sphe- 
noid, which completes with the palate-bone the sphenopalatine foramen ; thus it agrees 
entirely with the ethmovomerine lamina in its relations. If there be yet any link 
wanting to prove its identity with that lamina, we shall find it supplied when we examine 
the skull of the young Orang. 
In a foetus of the third or fourth month, the vomer consists merely of two alee which 
meet beneath the septal cartilage and form one bone. The inferior edge of the scooped 
bone so formed presents, in a foetus of the fifth or sixth month, a broad surface marked 
by a raphe in the middle line for articulation with the maxillaries strictly so called, i. e. 
the part behind the anterior palatine foramen (fig. 4, B). This surface narrows behind 
into a mere edge to articulate with the palatals ; while in front it ceases abruptly, and 
only the lamina bounding the groove is prolonged on the intermaxillary part of the 
palate. Already the intermaxillaries have begun to be elevated in the middle line above 
the level of the maxillaries, so as to form the crista incisiva, consisting of a process on 
each bone (“ semicrista incisiva” of Henle), and a groove between the two on such a 
level as to continue the groove of the vomer, which it does throughout life. 
In the skulls of young subjects (for example in the specimen referred to as No. 1 
(fig. 1, B), the vomer is seen in its most characteristic form. The alse have reached their 
maximum of development. At their posterior extremity is seen the thick dilated part 
which passes back beneath the sphenoid, and lies between the upper extremities of the 
pterygoids, which are sometimes called vaginal g)rocesses, but improperly, since they 
only lie edge to edge with the vomer and never sheath it. In front of the dilatation 
the margins of the alee continue for some distance to ascend as they pass forwards, and 
it is at this part, as far forwards as the points at which they begin to slope downwards, 
that the sphenoidal spongy bones are in contact with them. Also, by the elongation of 
the face, the vomerine groove has become sloped, while the extremity which rests on the 
crista incisiva is, by the increased elevation of that process, raised above the level of the 
maxillaries ; and the space thus left between the groove and the hard palate is spanned 
by a mesial plate, about one line deep in front and three behind. As the face developes 
further this mesial plate becomes deeper, and sometimes there is a process continuous 
with the anterior perpendicular edge of the mesial plate, sent downwards between the 
incisive foramina, behind the crista incisiva (fig. 4, A). This downward process is 
occasionally a separate bone, and is so in a specimen of mine taken from a subject 
* Henle mentions that the orbital process of the palate-bone “aids in closing the sphenoidal sinus 
when its wall is imperfect.” The condition which he refers to is no doubt that mentioned in the text. See 
Hexle, Elandbuch der System. Anat. des Menschen, i. 174. 
