CRANIAL SYMPATHETIC GANGLIA IN THE RAT 181 



types. It was not until some time later when reviewing a paper 

 by Weigner ('05) that the picture became clear. Weigner, in a 

 study of the nervus intermedins, both in man and in the marmot, 

 showed conclusively the presence of T-cells, typical cerebrospinal 

 ganglion cells, on the nervus petrosus superficialis major, the 

 chorda tympani, and especially at the exit of the nerve to the 

 stapedialis muscle. Bipolar cells were likewise encountered. 

 Weigner used material prepared by the Cajal method and there 

 was small chance for error. Rhinehart ('18) mentions a small 

 ganglion at the point where the chorda tympani leaves the 

 facialis trunk, probably of the same nature as the cells described 

 by Weigner, although this is not so stated. This point will be 

 considered later in connection with the facialis. 



In the case of the vagus, the two types of peripherally situated 

 neuroblasts are readily distinguishable. One possesses a large, 

 rather clear nucleus and a relatively large amount of deeply 

 staining cytoplasm ; the cell seems comparable in every way with 

 elements of the ganglion nodosum; these cells are, in some cases, 

 unipolar, but in the majority of instances, bipolar. In some 

 embryos they are to be found in continuous rows (fig. 24) all 

 the way from the ganglion nodosum to the origin of the inferior 

 laryngeal nerve. I have been able to differentiate them most 

 easily in v. Rath preparations, where the cytoplasm is intensely 

 blackened. The second type of cell, the type which the writer 

 recognizes as a sympathetic neuroblast, is distinguishable by its 

 smaller nucleus, more granular and grayish in its staining capacity, 

 and by the markedly smaller amount of cytoplasm. It seems 

 convenient for future reference to refer to the two cell types 

 as the 'large-cell' and the 'small-cell' type, respectively. The 

 recognition of the small-cell type as sympathetic in nature is 

 based on the following: 1) the cells resemble those elements 

 encountered in the superior cervical sympathetic ganglion and 

 its branches, notably the internal carotid nerve; 2) the cells 

 tend to group themselves in masses, and in these groups the 

 large-cell variety is usually absent; 3) the cells are found particu- 

 larly in those regions of the vagus trunk where available descrip- 

 tions of future conditions do not lead us to suspect the presence 



