1910.] IN TOADS OF THE GENUS BUFO. 383 



systematic value. Thus Bufo latifrons and Bufo regularis are! 

 so closely related to one another that some authors refer them to 

 the same species, yet they differ in that the former is devoid of 

 subcutaneous fat- bodies, whereas in the latter these structures 

 are constantly present. 



IV. The Function of the Subcutaneous Fat-Bodies. 



Conspicuous deposits of fat on the ventral abdominal wall are, 

 as is well known, of frequent occurrence in Reptiles (4), and the fat- 

 bodies of Bufo described above are similar in certain respects to 

 those found in Lizards on the course of the pelvic and ventral 

 abdominal veins. The latter veins in both Reptiles and in Bufo 

 remove the blood from the corpora adiposa and convey it to the 

 liver. 



The function of these bodies is difficult to ascertain exactly : 

 they are probably to be regarded as stores of food matter which 

 are drawn upon when necessary. This view is supported by the 

 fact that emaciated specimens have the fat-bodies much reduced, 

 sometimes scarcely visible. 



In order to further investigate this point a number of specimens 

 of Bufo viriclis were kept without food for a considerable time 

 (15 weeks) ; all showed great reductions in the size of the 

 fat-bodies as compared with those of well nourished specimens. 



I mentioned above that the corpora adiposa of this toad were of 

 greater size and contained more fatty matter in the females than 

 in the males ; examination of a number of specimens of B. calamita, 

 the Natterjack, and of the closely related African form, B. regularis, 

 showed this to be correct also of these species. It seems therefore 

 probable that the fat-bodies have also some relation to the repro- 

 ductive processes, as for example the production of large masses 

 of yolk and albumen for the eggs. 



Bibliography. 



1. Duges, Ant. — Recherches sur l'Osteologie et la Myologie des 



Batraciens. Paris, 1835. 



2. Leydig, F. — Die Anuren Batrachier der deutschen Fauna. 



Bonn, 1887. 



3. Cope. — The Batrachia of North America. Washington, 



1889. 



4. Butler, G. W. — " On the Relations of the Fat-Bodies of the 



Sauropsiola." Proc. Zool. Soc. 1889. 



5. Giglio-Tos, E. — " Sui Corpori grassi degli Anfibi." Atti Ace. 



Torino, xxx., 1895. 



