256 MR. youatt’s veterinary lectures. 
nerves. In the middle lobes, resting upon the same bone, I ob¬ 
serve the ovoid projection of the corpora striata, and the origins 
of the olfactory nerves from them ; and my attention is more 
particularly directed to the crura cerebri, or condensation of the 
medullary matter of the base of the brain. They are large white 
chords or pillars, beginning to appear opposite to the anterior 
portion of the corpora striata, and pursuing on each side a direc¬ 
tion inwardly and posteriorly towards each other. They contain 
some grey and dark-brown-coloured cineritious substance, in 
flakes and in masses, but no longer in striae. The crura, resting 
upon the wings of the sphenoid bone, gradually approximate, 
and a little before their point of union there is interposed be¬ 
tween them a small round medullary body. 
The Corpus Albicans. —When I say a small round medullary 
body, I am describing the corpus albicans, as it exists in the 
horse and in all ruminants and herbivorous animals. In the 
omnivora and the carnivora it is divided into two. This is an¬ 
other lesson of comparative anatomy. The corpus albicans is 
placed immediately posterior to the lower opening of the infun¬ 
dibulum. It would seem half to surround it, as if by its ele¬ 
vated edge to turn away, and direct to the anterior portion of the 
base of the brain, anv fluid that might descend the infundibu- 
lum. But of this we know nothing. 
The Tituitary Gland. —Placed immediately under the lower 
opening of the infundibulum, and separated from it by a lamina 
of dura mater, is the pituitary gland. This is a dark-reddish 
body of a compressed circular form, occupying the sella turcica 
of the sethmoid bone. It is flat interiorly, and convex towards 
the brain, and has every appearance of a glandular structure. 
The profusion of arterial vessels around it is almost incredible, 
and veins have been clearly traced from it into the cavernous 
sinuses on each side. Being placed immediately under the infun¬ 
dibulum, we are naturally induced to trace some connexion be¬ 
tween it and this apparent funnel-shaped passage, and likewise 
the other sinuses with which it communicates; but there has been 
no anatomical proof of this: it has never been shewn that the 
lamina of the dura mater is actually pierced, nor has any channel 
been pointed out through which the moisture so derived might 
be conveyed away. The pituitary gland has rarely seemed to be 
affected by any disease in the ventricles, or accumulation of fluid 
there. Here, again, we must confess our utter ignorance. There 
is no difference in the construction of the pituitary gland in dif¬ 
ferent animals, except that it seems to be proportionally larger in 
them than in the human being, and large in proportion to the 
quantity of medullary matter; while these specimens will shew 
