Analoniii (>/ ^[iislralidii Amphibia. 235 



siderable uiununt of coajiiiluin alon<j the ventral siirface of the 

 kidney, showinsr the presence of considerable lymph in the 

 ])()dy cavity also. How the presence of >o much water in the 

 bladder is related to the tremendous development of the 

 nephrostomes in this form is not at all easy to see, though there 

 is certainly an intimate relationship between the two facts. It 

 seems most probable that the water from the extremely thin- 

 wa.llrd bladder soaks out into the body-cavity, and is passed 

 back by the nephrostomes into the blood vascular system 

 whence what is required may be taken by the organs of the 

 body, the surplus being again excreted into the bladder, and so 

 on; thus maintaining a constant circulation of this water fur 

 the benefit of the body generally. This return of waste with 

 the water from the bladder would be less injurious than in 

 the ordinary frog, since in these aestivating frogs oxidation 

 of the tissue will be at a mininmm, probablj' only sufficient to 

 maintain life. 



Cystignat}iii)ai:. 

 Crinia si«;nifera. 



The general kidney arrangement does not call for any special 

 comment, the relationships of the kidney tubules, blood-spaces 

 and supportive tissue resembling those found in Hyla aurea. 

 The glomeruli are spherical, very few in number, and situated 

 close to the ventral surface. The nephrostomes also are very 

 few in number, what there are being chiefly at the anterior end. 

 Their walls, however, are veiy easily distinguishable from those 

 of the uriniferous tubules. They iwe often not much more thau 

 a slit, in ^ome cases no cavity or cilia being visible, but wherever 

 determinable, they open into the venous blood-spaces on the 

 ventral surface. 



The body cavity of this form also was injected, with the result 

 that the carmine was drawn through the nephrostomes into the 

 blood-spaces of the ventral one-third of the kidney, though to a 

 very much less extent thiun in other forms similarly treated. 

 The small number of nephrostomes. their frequently diminished 

 ■cavity, and their apparently smaller functional activity would 

 seem to indicate that in Crinia signifera, they are rapidly losing 



IOa 



