#>/^ 



Licrosco|ic Studies on the Central ]\"ervous 

 system of Reptiles and Batractians. 



By John J. Mason, M. D. 



ARTICLE I. THE SPINAL COED OF THE FROG RANA I'lI'IENS, 



RANA IIALECINA. 



[Reprinted from the Journal or Nervous and Mental Disease, Jan., 1880.1 



XT is not intended in these articles to give, in detail, an ana- 

 -*- toniical description of tlie nervous system of this chiss of 

 animals. So far as the anourous group of batrachians is con- 

 cerned, one could hardly effect such a purpose better tlian by 

 translating the works of either Keissner * or 8tieda,f which 

 together with those of Wyinan;}: and Ecker§ are in the hands 

 of most comparative anatomists. Only in writing of species, 

 the nervons system of which may not previously have been 

 studied, will a full description be attempted, the main object 

 being to present from time to time facts observed by the au- 

 thor, and regarded by him as supplementary. Tiie form of 

 the spinal cord and especially that of its enlargements ; the 

 nuclei of the nerve cells, and variations in their shape, size, 

 etc., in the same individual ; the number of ganglionic bodies 

 in the spinal cord, and their rehitions to the roots of the spinal 

 nerves, and the ditferences, if any, which may be determined 

 by sex : these, among others, seem to me to be subjects of 



^Der Dau des Ceutralen Nerveiisystems der Ungeschwdnzteii Batrachier. 

 Dorpat. 18G4. 



\Studkii ueber das Central NenowjKtem der Wirbelthiere. Leipzig, 1870. 



X Anatomy of the Nervous System of liana pipiens. Washington, 1853. 



'S^ [cones Physiologicm, 1851-59. Licpzig. " Die Anatomie des Frosches 

 des pliysiologisclieu Tliieres, ibtfur don Pliysiologen, kaum minder wicLtig, 

 als die Anatomie des Mensclien." 



