164 FRED W. STEWART 



nerves, at least as far anteriorly as the trigeminus. Since sympa- 

 thetic ganglia are known to be developed in relation to each 

 segmental spinal nerve and likewise possibly in connection with 

 the trigeminus of higher forms, their apparent absence in the 

 case of facialis, glossopharyngeus, and vagus leaves a curious 

 break in the morphologic chain of ganglia. With these facts 

 in mind, the writer undertook, some three years ago, a reinvesti- 

 gation of the origin of sympathetic ganglia in connection with 

 the cranial nerves, the facts ascertained being embodied in this 

 paper. 



HISTORICAL 



Numerous efforts have been made to account either for the 

 presence or absence of sympathetic ganglion cells developmen- 

 tally related to the facialis, glossopharyngeus, and vagus nerves. 

 Previous works dealing with the subject may be classified under 

 two general headings: first, those admitting and explaining the 

 absence of such cells; secondly, those seeking to recognize either 

 in the cerebrospinal ganglion or in the central nervous system, 

 a representative of the absent sympathetic ganglion. These 

 two general groups of interpretations obviously overlap. 



Perhaps the sole representative of the first of these groups 

 consists in a brief paper by Ariens Kappers ('08). If I am 

 correct in my interpretation of Kappers, his reasoning is 

 as follows: From numerous studies, both developmental and 

 comparative, Kappers has concluded that there exists in the 

 central nervous system some relation between the direction of 

 migration of the cell body of the neuron and the source of maxi- 

 mum stimulation; the cell body tends, namely, to move in the 

 direction whence maximum excitation proceeds. In the sympa- 

 thetic nervous system we are dealing with a migration of cell 

 bodies in a direction apparently exactly the reverse of the direc- 

 tion-type observed in the central nervous system. This vari- 

 ation is to be explained through the observations of Langley 

 and Anderson ('94) and afterward Langley alone (numerous 

 papers, '99, '00, '03) on the physiology of the axon-reflex. Kap- 

 pers ventures to suppose that the axon type of stimulation is 



