1908.] ANATOMY OF A FROG. 39 



§ Fai-Bodies. 



Although these organs are known to vary among the Aniira, 

 from individual to individual, from side to side of the body, and 

 also shrink or become expanded at different times in the life of 

 the individual *, I think it worth while to describe the appear- 

 ances seen in the two specimens which I dissected. In both of 

 them the fat-bodies were large and ajoparently fully developed. 

 In the female they were much the larger ; but then the female 

 specimen was considerably larger than the male, a difference 

 which I am disposed to put down as a sexual character. In the 

 female the fat-bodies extended forwards a long way and appeared 

 when the body was opened actually in front of the lungs. In 

 the male they were much smaller and firmly adherent to the 

 fi'ont margin of each testis f. Each fat-body was divided distally 

 into five or six finger-like processes of the usual shape. 



§ Renal Organs. 



The kidneys of Brevice2)s are like those of Rana in that they 

 are flat smooth bodies with no division into massive lobes such as 

 occurs among the Pelobatidse. They are represented in text- 

 fig. 13, which shows also the relations of the testes to them. 

 The only peculiarity which they show (so far as I have ascer- 

 tained) is the complete fusion in the middle line of the right and 

 left viscus in the male. In the female they are very closely 

 apposed but not fused. This fusion is, hoAvever, not complete ; 

 that is to say, the two organs in the male are not continuous with 

 each other in the middle line throughout the whole of their 

 length. It is only for about one-half of their extent that they 

 are thus fused. Anteriorly the two kidneys are quite distinct 

 until the emergence of the jDOstcaval vein which bends downwards 

 just in front of the point where the two kidneys become almost, 

 if not quite, soldered together. Posteriorly a larger free region 

 is left. 



The common duct thus formed does not, as it does in the case 

 of DiscoglossvjS and Alytes, enter the ureter direct without passing 

 through the kidney. In the present species the duct becomes 

 lost in the substance of the kidney in a way which I did not 

 follow out more minutely. In any case it did not bend round the 

 anterior end of the kidney to join the ureter. The two kidneys 

 are in very close contact below the testes. But the duct showed 

 no signs of division into a branch of each kidney, but appeared to 

 enter the middle line, and was at any rate concealed by kidney- 

 tissue before dividing. As the vasa efferentia referred to were 

 exceedingly obvious on inspection with a lens, I imagine that 



* Boulenger, " The Tailless Batrachia of Europe," Raj' Soc. Publication, 1897. 

 t I may observe that I found no " Bidder's Organ." 



