56 Drixon——On the Development of the Branches of the Fifth Cranial Nerve in Man. 
Goronowitsch, which disappear at a later stage, just as they do in the case of the 
ophthalmic nerve. 
At the end of the fourth week—Br,.—both superior and inferior maxillary 
nerves, possess more axis-cylinders than the ophthalmic nerve, and are thus further 
advanced in their development. Also at this time the superior and inferior 
maxillary divisions arise very close together, almost by a common stem, while both 
are at their origin widely separated from the ophthalmic. In the chick Remak, 
Marshall, His, Béraneck, Goronowitsch, and others, all describe the superior 
maxillary nerve, either as a later outgrowth from the Gasserian ganglion than the 
inferior maxillary nerve or as a branch of the latter nerve. A similar account has 
been given for the lizard by Béraneck, and for Petromyzon by Shipley. If we 
may judge from embryo br;., man differs from these lower forms in possessing a 
superior maxillary nerve which is formed early and independently of the inferior 
maxillary.* In the Guinea-pig, according to Chiarugi, the superior maxillary 
nerve is developed as a branch of the inferior maxillary.t 
It is interesting to notice that in Ru. (Sth week) the Vidian nerve is already 
present as an outgrowth from the geniculate ganglion of the facial nerve, and 
ends at some distance from the superior maxillary nerve. The connection of the 
Vidian nerve with Meckel’s ganglion, in older embryos and in the adult, must be a 
secondary one. This fact will be again referred to. I may say that in the rat 
the origin of the Vidian, or rather great superficial petrosal is easily proved to be 
from the geniculate ganglion of the facial. In this animal the nerve can be 
recognised as a fine twig, with many cells in its course, as early as the 13th 
day, stretching inwards from the geniculate ganglion towards the carotid artery 
(see figs. 4 and 5, p. 57). 
In C.R. (beginning of 6th week) and F.M. (7th week), and also in another 
embryo of about the same age, viz. Wt., the cells of Meckel’s ganglion are 
continuous with those of the otic by a narrow neck. This connecting neck of 
cells lies in part of its course inside the developing cranium to the inner side of 
the Gasserian ganglion. From its position this part of the cellular connection 
probably represents the aggregation of cells described for a human foetus by 
Ewart,¢ and thought by him to represent the ganglion of the nasal nerve. 
This close connection of the otic, with Meckel’s ganglion, is probably to be 
associated with the intimate relationship, that exists in the embryo, between 
superior and inferior maxillary nerves. 
* Kupffer’s recent account of the cranial nerves of Ammocoetes Planeri, shows that in this animal 
superior and inferior maxillary nerves arise at the same time from the Gasserian ganglion. ‘‘ Studien zur 
vergleichenden Entwicklungsgeschichte des Kopfes der Kranioten,” Heft. ii., Munchen, 1895. 
+ Monitore Zool. Ital., December, 1894, p. 275. 
+ On the Development of the Ciliary or Motor Oculi Ganglion.” Proceedings of the Royal Society, 
1889, vol. xlvii., p. 287. 
