'202 ALBERT KUNTZ 



considerable size. In view of the double origin of the other 

 sympathetic ganglia associated with the trigeminal nerve, we 

 should expect that both cells of trigeminal and of facial origin 

 should take part in the development of the submaxillary gan- 

 glion. The writer could not, in embryos 10 to 11 mm. in length, 

 trace the chorda tympani to its junction with the lingual nerve. 

 Neither did he succeed in determining the exact phase of develop- 

 ment in which this junction is effected. However, in view of the 

 condition of the other rami of the facial nerve, especially the 

 greater superficial petrosal nerve, in embryos in which the earli- 

 est traces of the submaxillary ganglion appear, it is safe to con- 

 clude that cells are aggregated in the path of the lingual nerve 

 before the junction of the chorda tympani with the latter is 

 effected. Therefore, the further conclusion that the earliest cells 

 w^hich enter the primordium of the submaxillary ganglion are 

 cells of trigeminal origin is also justified. It is quite probable 

 that cells which advance from the facial nerve along the chorda 

 tympani enter the primordium of the submaxillary ganglion after 

 the junction of the chorda tympani with the lingual nerve has 

 been effected. The primordium of this ganglion increases in 

 size relatively rapidly. In an embryo 13 mm. in length (no. 485), 

 as illustrated in figure 31, the submaxillary ganglion is repre- 

 sented by a relativel}^ large mass of cells. In sections of embryos 

 12 mm. and over in length which cut the lingual nerve transversely 

 at the level of the submaxillary ganglion, this mass of cells com- 

 pletely encircles the lingual nerve trunk. This condition ob- 

 tains for a considerable interval following the 12-mm. stage. 

 In view of the early phase of development represented by em- 

 bryos 12 and 13 mm. in length, it is inconceivable that any consid- 

 erable portion of the cell-mass which constitutes the primordium 

 of the submaxillary ganglion at this stage arose from cells which 

 have advanced thither from the facial nerve. Therefore, we 

 must conclude that the submaxillary ganglion arises primarily 

 from cells of trigeminal origin which advance distally along the 

 lingual division of the trigeminal nerve. This conclusion is in 

 accord with the work of Broman ('11) and Streeter ('12). Gan- 

 fini ('17) does not admit that in embryos of the guinea-pig and 



