224 Georglna Sweet : 



surfiMio of the kidney. He found the-iu in Rana, 

 But'o, Bomljinator and Discoglofsns. There may 

 be one nephrostonie to two tubules, or one to four 

 nephrostomes to one tubule. TTiey are connected 

 with the fourth part of the uriniferous tubule. 



1875. Meyer. [Ecker, pp. 328 and 336, and Marshall and 

 Bles, '90, p. 147]. Quite independently and un- 

 known to each other, Meyer confirms Spengel's 

 work. He found 250-360 in Rana. 



1877. Nussbaum. [Farrington, '93, p. 309], confirmed pre- 

 vious work as to the internal opening. 



1880. Nussbaum. [Ecker, p. 328, 336 : Nussbaum, '80], 

 stated that the nephrostonie is connected with the 

 neck of the tubule in the larva, but opened into 

 the Renal Portal Vein in the adult. 

 Weidersheim, according to Haslam [Ecker, p. 336], 

 at one time stated that the nephrostomes had no 

 openings ait all on the surface. 



1886. Nussbaum and Wichmann. [Marshall and Bles, "90, 

 p. 150]. Tliese found that in Rana fusca, R. 

 e.sculenta, Biifo calamites, and Alytes obstetiicans, 

 they open into the Renal Veins and so to the 

 Inferior Vena Cava. 



1886. Hoffmann. [Hoffman, '86], asserted that they end 

 blindly in the adult, though connected with the 

 neck of the capsule in the larva. 



1886. Wiedersheim. [Wiederslieim, 86, p. 756], accepts 

 Nussbnum's work of 1886 with the remark that 

 the peritoneal fluid is no longer lost, but is re- 

 turned to the general circulation like the re«t of 

 the lymph. 



1889. Hiijslam. [Ecker, p. 336], states that he could not 

 find any trace of them, and that if present (1) they 

 are very difficult to find, (2) they do not form a 

 free communicating path between any part of the 

 uriniferous tubules and the abdominal cavity, and 

 (3) their superficial terminations have no free 

 cilia 



