2/2 FROM FISH TO PHILOSOPHER 



nuity: the fishes, Amphibia, and presumably the nascent 

 amniotes were ureotelic (that is, characterized by urea 

 excretion) and the mammals have simply persisted in 

 this habitus. This issue has been confused as a conse- 

 quence of the misinterpretation of nitrogen excretion in 

 the fishes, as noted in the last technical note accompany- 

 ing Chapter VI. 



X. THE MAMMALS 



136. Grafflin, a. L. The normal, the acromegalic and 

 the hyperplastic nephritic human nephron. Archives 

 of Pathology, 27: 691. 1939. 



137. Simpson, G. G. The beginning of the age of mam- 

 mals. Biological Reviews, 12: 1. 1937. 



138. Smith, H. W. Principles of Renal Physiology. Ox- 

 ford University Press, Nevi^ York, 1956. 



139. Smith, H. W. The fate of sodium and water in the 

 renal tubules. Bulletin of the "New York Academy of 

 Medicine, 2nd Series, 35: 293. 1959. 



140. Smith, H. W. Highlights in the history of renal 

 physiology. The Georgetown Medical Bulletin, 13: 



4- 1959. 



141. Smith, H. W. The Kidney. In: The Fabric of Car- 

 diovascular Concepts. Edited by A. P. Fishman 

 and D. W. Richards. Oxford University Press, New 

 York. 



142. Sperber, Ivar. Studies on the mammalian kidney. 

 Zoologiska Bidrag Fran Uppsala, 22: 252. 1944. 



The evolution of the mammals is discussed by Simp- 

 son {137}, Romer {41, 44}, Gregory {33}, and Young 



{73}. 



The only reconstructions of entire human nephrons, 

 including the thin segment, are those of L. A. Turley, 

 vy^hich have been described by Graflflin {136}. 



The comparative anatomy of the kidney as a whole 

 and of individual nephrons in a wide range of mam- 

 mals is available in Sperber's excellent monograph {142}. 



