Av<(t(jiiii/ of A a^traliaa Aui'pldhid. 233 



teriorly where the venous spaces form nearly half the thickness 

 of the kidney, and diminish in number somewhat irre<:n^ilarly 

 towards the anterior end. In one kidney alone I counted 1067 

 external openings of nephrostome funnels : I have seen sus many 

 as 1(1 external openings in a single thin section across one 

 kidney. There are here several totally different types of 

 nephrostumes. The first are the normal ones like those found 

 most frequently in Hyla aurea. which are wide, Sihort and un- 

 Ijranched, and run almo>t hnrizonta*lly beneath the kidney sur- 

 face, and emjftyinu' directly into the main venous spaces, very 

 much like that figured for another form in Fig. 4. except that 

 there is no supporting tissue in Notaden bennetti. The second 

 set, although resembling some of those in Hyla aurea in that 

 they branch, are quite distinct from those in the sjtructure of 

 the " funnel.'' This is long, narrow and more tubular than in 

 any form previously described : it branches freely, running a 

 considerable distance into the centre of the kidney. The 

 branches, of which there may be as many a.s five from one 

 nephrostome, run generally along the trabeculae and then leav- 

 ing them, end in a blood-.- pace. There I believe them to open, 

 though I have not been able to detect the actual aperture. 

 These nephrostomes are especiaiUy numerous on either side of 

 the main venous space. 



Just within the inner and outer edges of each kidney, es- 

 pecially in the outer edge, are here and there coils of small 

 thin-walled tubes, whose cells have deeply staining nuclei, resem- 

 bling generally the second or branching type of nephrostomial- 

 tubule. Sometimes these open clearly to the exterior — ^ome 

 even on the dorsal side of the outer edge and anteriorly 

 (though still through the peritoneum which often is continued 

 on to the d')rsal side of the kidney for a short distance) — at 

 other times they do not open, but are still connected with the 

 surface of the kidne}% and may end blindly internally in a 

 swollen mass of cells — or. one, two, or three nephrostomes may 

 open into a sinirle uriniferous tubule in its ith part — or, yet 

 again, may apparently come into relationship with a smaller 

 tvpe of Malpighian body than that usual elsewhere, while in 

 yet others, the Malpighian body is still there, but is ver^- de- 

 generate. 



10 



