NERVE TERMINI IN THE SKIN OF THE COMMON 



FROG.^ 



By G. E. CoGHiLL. 



PART I. 

 With Plates IV and V. 



The study here presented is a continuation of that which 

 was begun last year under the direction of President Herrick 

 and the results of which were published in Vol. VIII, Nos. i 

 and 2 (combined) of this Journal, under the caption, "The 

 Somatic Equilibrium and the Nerve Endings in the Skin."^ In 

 this discussion we dealt with the skin of both Anura and Uro- 

 dela. In the present study the frog only is considered ; and 

 the points further discussed here which were presented on pp. 

 37-51 of the volume referred to are: the isolated sensory cell 

 or terminal cell, the ganglionic plexuses, and nerve termini on 

 glands. Our belief with reference to these structures is sup- 

 ported by methods not used formerly, and other conditions re- 

 lated to them have come to our notice. The latter have to do 

 chiefly with the musculation and innervation of certain glands. 



The results of our earlier study of the nerve endings were 

 obtained by the haematoxylin, picrocarmine and methylene blue 

 stains, and by the use of chrom-acetic acid solutions as fixing 

 agents. For fixing we have since used other modifications of 

 the chrom-acetic acid preparations, and Flemming's solution in 



1 Thesis presented for the degree of Master of Science at the University of 

 New Mexico. 



' The present installment includes simply the author's results; an historical 

 resume may be expected with the second part which will be devoted to the 

 erobryogenesis of the skin. 



