168 FRED W. STEWART 



or in other words suggestive of a higher synapse. The reader 

 is referred to the paper in question for discussion. Langley ('03), 

 in discussing the sympathetic action of the vagus, concludes 

 that the ganglion nodosum is not concerned with efferent 

 impulses. 



Earlier advocates of the interpretation that some portion of 

 the sympathetic remains behind incorporated into the substance 

 of the cerebrospinal ganglion, may have derived evidence from 

 Gaskell ('86). The latter inferred the presence of non-medul- 

 lated fibers in the vagus trunk, but failed to find them in the 

 root; his consequent conclusion was that these non-medullated 

 fibers of the vagus trunk were postganglionic fibers arising from 

 small cells of the nodose ganglion. Dogiel ('08), however, de- 

 scribed non-medullated axons associated with small cells in 

 spinal ganglia; Cajal ('06) confirmed Dogiel's observations and 

 furthermore showed the axons to be of the T- or Y-shaped variety, 

 and Ranson ('11, '14, and '15) has shown that the axons of these 

 small cells constitute the non-medullated fibers of the peripheral 

 branches of the spinal nerves, and has proved them present both 

 in the trunk and the root of the vagus. 



Streeter ('12) suggests that representatives of the sympathetic 

 ganglia of the facialis, glossopharyngeus, and vagus nerves may 

 be present in cells which have remained within the confines of 

 the neural tube or of the sensory ganglion. This possibility is 

 again suggested in connection with the failure of cells of oculo- 

 motor origin to contribute to the ciliary ganglion of human 

 embryos. 



In certain lower forms there is good evidence for believing that 

 cranial sympathetic ganglia are present in connection with the 

 facialis, glossopharyngeus, and vagus nerves. Anatomical or 

 histological studies show them present at least in teleosts (Stan- 

 nius, Hi, '49, '54; Herrick, '99, '00; His, Jr., '93). Neumayer 

 C06), in Hertwig's Handbuch, states that in selachians cranial 

 sympathetic ganglia other than the ciliary are absent. Johnston 

 C06) states that the development of cranial sympathetic ganglia 

 reaches so great a magnitude in teleosts that it is to be hoped 

 that it will be discovered in selachians. His, Jr., ('93) found 



