228 Georg! iia S/veet : 



Hylidae. 



ffy/a aurea. 



This niJiy be taken as the normal type. [See PI. XX., tii^. 1.] Iii 

 ti'ansverse section the kidne}^ is more or lesss triangular, the base 

 being towards the middle line of the body. The branches of the 

 Renal Veins occupy much of the outer part of the ventral side, the 

 Renal Arteries entering nearer the inner edge of the kidney. The 

 peritoneum is continued dorsally on the kidney for a short 

 distance from the outer edge, but leaves the kidney well before 

 it reaches the inner edge of the ventral surface. An '' fudrenal 

 body " is present on the ventral part of each kidnej'. 



The fibrous connective tissue supporting the tubules and 

 blood-ves-els is present here, to much the same extent as in 

 Ranai, Avhere it has lieen known as "kidney-parenchyma" by 

 .some Gerniau writers [Cf. PL XXL, tig. 3.] Tlie i\Ial])igliiau bodies 

 are often very much elongated, but not always, their gi'eatest 

 length being found in the inner part of the kidney. They form 

 a more or less irregular layer in the upper part of the ventral 

 lialf of the kidney. The neck emerges, from the dorsal j^art 

 of the Capsule, and rvms more or less vertically upwards. The 

 blood-vessels enter and leave the side of the glomerulu.s. There 

 are no special points of difference in the microscopic structure of 

 the tubules cajlling for comment^ — the pavement epitiielium of Bow- 

 man's Cap«ule, the ciliated cubical epithelium of the neck, the 

 large-celled convoluted portion often pigmented, and the col- 

 lecting tubes with their wider cavities and more or less cubical 

 epithelium, being very similar to corresponding parts found in 

 other forms such as Rana. 



Under favourable conditions, there may be seen under a hand- 

 lens numerous minute pit-like structure.^ on the ventral surface 

 of the kidney. These are the externail openings of the 

 nephrdstomes. These funnel-shaped deprassions are situated 

 chietiy on the inner lialf of the ventral surface of the kidney, 

 and pierce the peritoneum which is loosely attached to the 

 kidney wall. The walls of the " funnel " are formed of large 

 cubical fla«2:ellated cells, with round, sharply defined nuclei — the 

 flagella are always directed inwards, away from the surface of 

 tlie kidney. [Cf. PI. XXI., fig. 3.] Throughout tliis paper, the 



