18U ALBERT KUNTZ 



of vertebrates above the Elasmobranchii. According to his ob- 

 servations, the gangha of the sympathetic trunks arise from 

 ' neuroc^ytes ' which advance peripherally both along the dorsal 

 and ventral roots of the spinal nerves. From the primordia of 

 the sympathetic trunks cells advance farther ventrally and give 

 rise to the ganglia in the plexuses along the abdominal aorta. 

 The enteric plexuses, according to Ganfini, arise from cells de- 

 rived from the primordia of the sympathetic trunks which 

 advance farther ventrally and enter the walls of the digestive 

 tube. He recognizes cells which advance distally along the vagi 

 and enter the pulmonary, the cardiac, and the oesophageal 

 plexuses, but he seems to be of the opinion that these cells migrate 

 from the superior cervical ganglia. He also recognizes the double 

 origin of the ciliary ganglion in the lower vertebrates. While he 

 finds the contribution to this ganglion of cells which advance 

 distally along the oculomotor nerve less obvious in mammalian 

 embryos than in embryos of lower vertebrates, he does not ex- 

 clude it even in embryos of this class of vertebrates; consequently, 

 his conclusions regarding the development of the ciliary ganglion 

 are in essential accord with those of Carpenter and the present 

 writer. The sphenopalatine, the otic, and the submaxillary 

 ganglia, according to Ganfini, are derived primarily from the 

 semilunar ganglion. 



The most recent work on the development of the cranial 

 sympathetic ganglia is that of Stewart ('20) which is based on 

 embryos of the rat. With respect to all these ganglia, except 

 the ciliary, Stewart has adhered strictly to the theory that the 

 cells whieh give rise to each respectively advance peripherally 

 along the nerve, or nerves, which, in the adult, carry its pregan- 

 glionic fibers. His findings will be considered further in a later 

 section of this paper. 



The scattered observations on the development of the sympa- 

 thetic nervous system in human embryos which were published 

 prior to 1910 were reviewed by Streeter ('12), who also recorded 

 his observations. Further studies based on human embryos 

 were published by Broman ('11). The work both of Streeter 

 and Broman is in general accord with that of the earlier investi- 



