42 The Ohio Journal of Science [Vol. XVII, No. 2, 



have a distinct r. oph. prof, but fused Gasserian and profundus 

 ganglia. The results of this study show that for Plethedon 

 at least the ganglia of the adult are formed by an actual fusion 

 of the profundus with the Gasserian without loss of cells by 

 the profundus portion. This would not warrant the conclusion 

 that the same process occurs in types where there is a loss of 

 the r. oph. prof, nerve, but it throws an interesting light on 

 the mode by which the process of reduction ending in loss of 

 both profundus ganglion and nerve began in phylogeny. 



LITERATURE CITED. 



1897. Allis, E. P. Jr. The cranial muscles and cranial and first spinal nerves in 

 Amia calva. Journ. Morph., vol. 12, no. 3. 



1901. Bowers, Mary A. The peripheral distribution of the cranial nerves of 



vSpelerpes bilineatus. Proc. Amer. Acad., vol. 36. 



1902. Coghill, G. E, The cranial nerves of Amblvstoma tigrinum. Jour. Comp. 



Neurol., vol. 12, pp. 205-289. PI. 15-16. 



1899. Herrick, C. Judson. The cranial and first spinal nerves of Menidia; a 

 contribution upon the nerve components of the bony fishes. Jour. Comp. 

 Neur., vol. 9, pp. 153-455. 



1912. Landacre, F. L. The epibranchial placodes of Lepidosteus osseus and their 



relation to the cerebral ganglion. Jour. Comp. Neur., vol. 22, no. 1. 



1913. Landacre, F. L. and McLellan, Marie F. The cerebral ganglia of the 



embryo of Rana pipiens. Jour. Comp. Neur., vol. 22, no. 5. 



1908. Norris, H. W. The cranial nerves of Amphiuma means. Jour. Comp. 

 Neur., vol. 15, no. 6. 



1908. Streeter, G. L. The peripheral nervous system of the human embryo 

 at the end of the first month. (10 mm.) Am. Jour. Anat., vol. VIII, 

 no. 3. 



1895. Strong, Oliver S. The cranial nerves of Amphibia. Jour. Morph., vol. 10, 

 no. 1. 



1892. Wilder, H. H. Die Nasengend von Menopoma alleghanense und Amphiuma 

 tridactylum nebst Bemerkungen uber die Morphologic des R. opthelmicus 

 profundus trigemini. Zool. Jahr. Abth. f. Anat. u. Ontog. Bd. 5, Heft 2, 



