740 AELES. [VoL. XII. 
foramen lying immediately in front of the lateral wing of the 
parasphenoid. It thus, like the external carotid, pierces a 
part of the chondrocranium, but does not enter the cranial 
cavity proper. In the orbital opening of the eye-muscle canal 
it receives a small branch from the internal carotid, and 
issues into the orbit with the recti muscles. 
6. The hypophysis cerebri and saccus vasculosus, in the 
adult, are both glandular structures. Both receive a consider- 
able nervous supply directly from the base of the infundibulum, 
and the glandular cavities of both communicate directly with 
the infundibular cavity. 
7. The olfactory nerve, contrary to Sagemehl’s statement, 
lies exposed to the orbit through a limited part of its course. 
The opening through which it is so exposed lies at the extreme 
front and upper end of the orbit, and gives passage to a vein 
coming from the nasal pit. The olfactory canal in front of 
the opening is, therefore, formed by the fusion of two canals, 
the anterior part of the olfactory canal proper, and what is 
probably the homologue of the orbito-nasal canal of selachians. 
The opening can, therefore, be called the orbito-nasal opening 
or fenestra. 
8. The “hitherto undescribed cranial nerve”’ of Pinkus, in 
Protopterus, is found in Amia, part of its fibres arising with 
the olfactorius and part of them having the intercranial course 
described by Pinkus, though their definite origin from the 
brain, as in Protopterus, was not satisfactorily determined. In 
the nerve the large cells described by Pinkus are found, scat- 
tered along the nerve in old larvae, but in 12 mm. larvae 
gathered into a knob-like protuberance on the under surface of 
the nervus olfactorius at about the middle of its length. In 
the latter larvae the collection of cells on the olfactorius 
resembles, in general histological appearance, the ciliary gan- 
glion found on the nervus oculomotorius in much the same 
relation to that nerve. As the ciliary ganglion is unquestion- 
ably, in part at least, a sympathetic ganglion, the ganglion on 
the olfactorius is, perhaps, of a similar character, and is pos- 
sibly the sphenopalatinum of higher vertebrates. 
g. The muscles rotating the eyeball in the several orders of 
5] 

