Drxon— On the Development of the Branches of the Fifth Cranial Nerve in Man. 69 
15. Soon the fibres of the superior maxillary nerve spread out horizontally, 
and are not collected so compactly into a single bundle as are the fibres of the 
other two divisions of the fifth nerve. 
16. All the important branches of the superior maxillary are present in an 
embryo of seven weeks. 
17. Meckel’s ganglion is present as a distinct cellular mass at the beginning of 
the sixth week. 
18. Meckel’s ganglion, in the embryo, is closely connected with the otic 
ganglion. 
19. The inferior maxillary nerve is at first unbranched. 
20. The first formed part of the inferior maxillary represents the inferior 
dental of the adult. 
21. The lingual nerve is formed later, and is not recognisable in the fifth 
week. 
22. Meckel’s cartilage presents a close relation to the branches of the inferior 
maxillary nerve, and seems to determine the directions which they take. 
23. All the important branches of the inferior maxillary nerve are represented 
in the embryo at the beginning of the sixth week. 
24. At the beginning of the sixth week the otic and submaxillary ganglion are 
present. 
25. The chorda tympani, the Vidian, and the nerve of Jacobson, are not, 
branches of the fifth nerve, inasmuch as they are not developed from it. 
26. The chorda tympani and Vidian nerves are branches of the facial, being 
developmentally derived from this nerve. The nerve of Jacobson is, in like 
manner, a branch of the glosso-pharyngeal. 
27. The origin of these nerves in man is precisely similar to what is observed 
in the rat. 
28. There is no direct evidence to prove, that the cells of the accessory 
ganglia of the fifth nerve, are derived directly from the cells of the Gasserian 
ganglion. 
29. ‘The sympathetic, associated with the carotid artery in the adult, is repre- 
sented in the embryo by fibres chiefly derived from the trunk ganglion of the 
Vagus nerve. 
I have to express my indebtedness to Professor J. M. Purser for a large series 
of beautifully preserved rat embryos of different ages, and also to Professor 
D. J. Cunningham for much help and valuable criticism. 
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