V. KuPFFER, Cranial JVerves of Vertebrates. 327 



vagus, but the formation of epibranchial ganglia from elas- 

 mobranchs on to mammalia is clearly established through 

 their works. There remains on this side the evidence that 

 the epidermis also participates in the principal ganglia. 



There cannot be the least doubt but that the fusions, de- 

 scribed by Van Wihje, of the ventral twigs of the facialis, 

 glosso-pharyngeus and vagus with thickened places in the 

 epidermis on the upper hinder wall of the pertaining gill 

 clefts correspond to the places of formation of the epi- 

 branchial ganglia. Besides the local relations to the gill 

 clefts or pouches, the circumstance that these places are de- 

 scribed as starting points for the branchial terminal twigs: 

 the rami post- and praetrematici also argue for this. In 

 sagittal sections these terminal twigs appear, in fact, as out- 

 growths of these ganglia, while cross sections teach that the 

 epibranchial ganglia have, indeed, an essential but not exclu- 

 sive share in the formation of the NN. branchiales. 



For a time I was of the opinion that the more dorsally 

 situated places of fusion of the dorsal branches of the cranial 

 nerves with the epidermis, which Van Wihje mentioned, 

 could be brought into connection with the formation of the 

 principal ganglia. But on closer examination of the rela- 

 tions, this conjecture proves untenable. These dorsal branches 

 in Selachians are purely cutaneous sensory nerves; the thick- 

 ened patches of epidermis furnish the lateral organs, remain- 

 ing in connection with the epidermis, and their peripheral 

 nerve apparatus. On the other hand, the lateral portions of 

 the principal ganglia have nothing to do, directly, with the 

 sense organs; they separate cleanly from the epidermis, 

 which shows thereupon a marked thinning, and move deeper 

 within. 



Beard has occupied himself more particularly than Van 

 Wihje with these epidermal formations; only it is difficult 

 to get a clear idea of the particulars from his publications, 

 since this active investigator is so filled with his hypothesis 

 of the branchial sense organs that his exposition of the de- 



