Dixon—On the Development of the Branches of the Fifth Cranial Nerve in Man. 37 
Inferior Maxillary Division of the Fifth Nerve. 
Br;. (4 weeks 6°9 mm.). Figure 14, Plate II. 
The inferior maxillary nerve takes origin from the lower end of the Gasserian 
ganglion, and passes forwards, downwards, and a little outwards. Near its 
termination, however, its course is almost vertically downwards. The inferior 
maxillary nerve in this embryo is a little longer than the superior maxillary, its 
length being 0:5 mm. nearly. 
There is a bundle of fibres which les between the superior and inferior 
maxillary trunks, but connected, apparently, with the inferior maxillary. These 
Fievre 4. Fiaure 6. 
Outline of portion of horizontal section through the head Camera lucida drawing of a portion of the section, the 
of a rat embryo of 14 days to show a very early condition of outline of which is given in fig. 4. The great superticial 
the great superticial petrosal nerve. A. carotid artery. petrosal nerve is seen growing out from the geniculate gang- 
Aud. internal ear. J. jugular vein. M. Medulla. Ph. lion of the facial nerve towards the carotid artery. Among 
eayity of pharynx and Eustachian tube. VII. facial nerve. the fibres of the developing nerve a great number of nuclei 
VIT’. geniculate ganglion of facial. The dotted outline in- are seen. 
dicates part of the ganglion of the VIII. nerve. 
fibres are chiefly derived from the motor root of the trigeminal, and lying above 
the inferior maxillary nerve pass more outwards than the inferior maxillary itself. 
The length of these fibres is not more than 0-2 mm., and they probably represent 
the motor branch of inferior maxillary nerve, seen in older stages. They are not 
figured by Professor His in the Paper already referred to. Many nuclei are 
present among the fibres of the inferior maxillary nerve, but no aggregations of 
these to form either otic or submaxillary ganglia are present. 
