SYMPATHETIC GANGLIA 257 



SUM]VIARY 



1. The sympathetic gangha on the cranial portion of the sym- 

 pathetic trunks arise, in embryos of the toad fish, primarily from 

 cells derived directly from the first spinal ganglion and the cere- 

 bral ganglia associated with the X, VII, and V cranial nerves. 

 Certain of these ganglia receive cells also which advance peripher- 

 ally from the neural tube along motor nerve-roots. The ciliary 

 ganglion arises in the path of the oculomotor nerve primarily 

 from cells which advance peripherally from the mesencephalon 

 along this nerve. It later receives a relatively small number of 

 cells which advance peripherally from the Gasserian ganglion and 

 the first sjaiipathetic ganglion associated with the latter along 

 the radix ciliaris longa. 



2. A permanent ciliary ganglion is probably not developed in 

 Amblystoma. In larvae of the frog, the ciliary ganglion arises 

 in essentially the same manner as in embryos of the fish. Other 

 distinct cranial sympathetic ganglia probably do not occur in 

 the Amphibia. 



3. In embryos of the turtle, the ciliary ganglion arises in the 

 path of the oculomotor nerve primarily from cells which advance 

 peripherally from the mesencephalon along this nerve. After 

 this ganglion has become connected with the ophthalmic nerve it 

 receives a relatively small number of cells which advance periph- 

 erally from the Gasserian ganglion. 



The sphenopalatine ganglion arises, in embryos of the turtle, 

 in the path of the great superficial petrosal nerve and soon becomes 

 connected by fibrous rami with the maxillary nerve. It arises 

 from cells which advance peripherally from the geniculate and 

 the Gasserian ganglia respectively along the great superficial petro- 

 sal and the maxillarj^ nerves. 



Ganglia homologous with the otic and the submaxillary gan- 

 glia of the higher vertebrates were not observed in embryos of 

 the turtle. 



4. In embryos of the chick, the ciliary ganglion bears the same 

 genetic relationships to the oculomotor and the ophthalmic 



