CRANIAL SYMPATHETIC GANGLIA IN THE RAT 



183 



gation of these cells at the origin of the superior laryngeal nerve 

 and another at the origin of the recurrent nerve. Caudal to 

 the origin of the latter nerve the large cells are but rarely en- 

 countered. The small-cell type is of much more general occur- 

 rence. They are found in large numbers in and along the vagus 

 trunk (fig. 3); they are likewise found in especially large aggre- 

 gates at the origin of the recurrent nerve (fig. 4) ; they are dis- 

 cernible in the cardiac branches of the vagus, in the pulmonary 



Fig. 4 Rat embryo, 15f days, vom Rath's technique. Neuroblasts of vagus 

 trunk, at origin of N. recurrens. Projection drawing, X 500. 



branches, on vagus fibers in the mesenchyme between trachea 

 and esophagus continuous with similar aggregates in the main 

 trunk, and in the gastric and intestinal mesenchyme (figs. 5 

 and 6). The entire vagus has become in fifteen and three- 

 quarter day embryos the site of neuroblastic differentiation. 



Attention may be called at this time to the fact that no such 

 pictures as are indicated in the figures of Kuntz ('09), for the pig, 

 have been obtained in the case of the rat. Although fifteen and 



