244 Georgind Sweet : 



4. Those of the second type fire unbranched nephro-toine*! 

 openino; into the uriniferous tubules, as first described by 

 Spengel in Rana. Tliese are found in Notaden bennetti only. 



5. The third type consists of branched nephrostomial tubules 

 opening into the venous spaces. Tliese are found in all forms, 

 and especially well developed in Notaden bennetti. 



6. The fourth type is also branched nephrostomiajl tul)es 

 opening however into the uriniferous tubules. This is found in 

 Notaden bennetti only. 



7. The fifth type is a^ third form of branched nephrostome 

 tube, which is closed at either or both ends. Tbese are only 

 known in Notaden bennetti. 



8. It will thus be seen that in all forms, nephrostomes open- 

 ing into the Renal Veins are present, these being the only type 

 present in most; in one form Notiiden l:'ennetti, all five kinds 

 of internal connections are found. 



9. It appears evident that these structures are undergoing 

 very rapid modification at the present time. 



10. In Notaden bennetti and Chiroleptes alboguttatus, the 

 vascularity of the kidney is very strongly marked — the 

 uriniferous tubules appearing to lie in a series of much branched 

 sinuses — the epithelial lining being in many cases almost im- 

 possible to determine. Tlie same is true, though to a less ex- 

 tent, in Heleioporus pictus. The vascularity would thus ap])ear 

 to be associated with the capacity of these frogs for storing 

 water in the urinary bladder while aestivating in their burmws 

 during the dry seasons. 



11. There is also a marked difference in the number of 

 nephrostome openings in one kidney from a minimum of 3U in 

 Hyla lesLieurii, to a maximum of 1067 in Notaden bennetti. 



12. Hyla lesueurii and Crinia signifera are tlie most do 

 generate in respect of their nephrositomes. 



13. Evidence from frogs injected with carmine indicates 

 that the nephrostomes do functinn for the conveyance of 

 material from the body cavity inro the kidney. 



14. In all forms, the Vasa eti'erentia enter the kidney just 

 external to the Renal Arteries. 



15. In Heleioporus pictus a well-marked limgitudinal Bid- 

 der's canal is present, as possibly also in Ilyla aurea, though 



