244 ALBERT KUNTZ 



. Cranial extension of sympathetic trunk 



In larvae of the frog 10 mm. in length or in larvae of 

 Ambly stoma of corresponding age, the sympathetic trunks are 

 already well established. However, no fibrous ramus can as yet 

 be traced cephalad from the superior cervical ganglion. In larvae 

 of the frog 13 to 15 mm. in length, a fibrous process may be traced 

 cephalad from the superior cervical ganglion to the level of the 

 Gasserian ganglion. It extends along the ventro-mesial aspect of 

 the vagus ganglion, then tends mesially and continues cephalad 

 approximately parallel with the cerebro-spinal axis . No ganglionic 

 enlargements occur in the course of this fibrous process nor were 

 any aggregates of cells which could be interpreted as sympathetic 

 ganglia observed associated with any of the cranial nerves except 

 the oculomotor. 



According to Camus ('12), no distinct sympathetic ganglia 

 associated with the sympathetic trunk are present in the frog 

 anterior to the superior cervical ganglion. According to this 

 author, the fibrous process extending cephalad from the superior 

 cervical ganglion may be traced, in larvae 13 mm. in length, as 

 far as the level of the Gasserian ganglion. The fibers of this 

 process decrease in number as it continues cephalad ; some of them 

 mingle with the fibers of the abducens nerve, others enter the 

 ophthalmic division of the trigeminal nerve. 



My observations on larvae of Rana and Amblystoma add noth- 

 ing, regarding the extent of the cranial sympathetic nerves and 

 the distribution of their fibers, to the findings of Camus referred 

 to above. Like the latter author, I am also of the opinion that 

 no distinct sympathetic ganglia associated with the sympathietic 

 trunk are present in the Amphibia anterior to the superior cer- 

 vical ganglion. Neither could cell-aggregates which could be 

 interpreted as sympathetic ganglia be observed farther periph- 

 erally in the cephalic region. As is well known (Strong '95), 

 sympathetic ganglion cells occur, in the Amphibia associated with 

 certain of the cranial nerves. Such cells, however, could not be 

 traced with certainty in my preparations. 



