LITERARY NOTICES. 



Development of the Fifth Nerre in Man.^ 



This research was conducted upon the series of human embryos 

 belonging to Professor His and is the first complete account of the 

 development of the fifth nerve of man. 



Professor His has described ^ the early development of the fifth 

 nerve up to the time when the three great divisions are separated. 

 Beginning at this stage with an embryo of four weeks, Dr. Dixon has 

 followed the subsequent development of the rami and their ganglia. 

 The observations on human embryos were controlled with rat embryos 

 of various ages and they were found to correspond in every impor- 

 tant particular. Transparent models of the various stages were con- 

 structed by transferring camera drawings of the sections to glass 

 plates. 



Ophthalmic Division. — At the beginning of the sixth week (13.6 

 mm.) nasal and frontal rami have developed and in connection with 

 the latter the ciliary- ganglion. The nerve passes through the ganglion 

 as a solid bundle, no fibers wandering out among the ganglion cells. 

 The fourth nerve communicates with the frontal proximally of the 

 ciliary ganglion and the remainder of its fibers at this stage enter the 

 ciliary ganglion and terminate in it. The third nerve at this stage 

 does not enter into relation in any way with either the ciliary ganglion 

 or the fifth nerve. The fourth nerve has a broad communication with 

 the frontal at seven weeks also. At the eighth week the third nerve 

 sends a branch to the ciliary ganglion, the latter sends twigs to the 

 eyeball, and the nerves of the orbit have practically the disposition 

 that obtains in the adult. The nasal nerve runs through the ciliary 

 ganglion, while the frontal has no connection with it. The ganglion 

 found in the sixth week in connection with the fourth and frontal 



' Dixon, A. Francis. On the Development of the Branches of the Fifth 

 Cranial Nerve in Man. Trans. Roy. Dublin Society, Ser. 2, VI, May, 1896, pp. 

 19-76. 



2 Abhandl, Kgl. Sachs. Ges. d. Wiss. 1888, XIV, p. 341. 



