TECHNICAL NOTES AND BIBLIOGRAPHY 2/5 



157. Schmidt-Nielsen, K. and R. Fange. Salt glands in 

 marine reptiles. 'Nature, 182: 783. 1958. 



158. Schmidt-Nielsen, K., C. B. J0rgensen and H. 

 OsAKi. Extrarenal salt excretion in birds. American 

 Journal of Physiology, 193: 101. 1958. 



159. Schmidt-Nielsen, K., and B. Schmidt-Nielsen. 

 Water metabolism of desert mammals. Physiologi- 

 cal Reviews, 32: 135. 1952. 



160. Schmidt-Nielsen, K. and W. J. L. Sladden. Nasal 

 salt secretion in the Hmnboldt penguin. Nature, 

 181: 1217. 1958. 



161. Smith, H. W. The composition of m±ie in the seal. 

 Journal of Cellular and Comparative Physiology, 7: 



465. 1936. 



162. Vimtrup, Bj., and Bodil Schmidt-Nielsen. The 

 histology of the kidney of kangaroo rats. Anatomi- 

 cal Record, 114: 515. 1952. 



Observations on the osmotic concentration in the blood 

 and urine of whales and other marine mammals are cited 

 by Krogh {65}, Smith {161}, and Prosser et al. {54}. 

 Clarke and Bishop {147} discuss the nutritional aspects 

 of plankton, and point out that when the sea water is 

 squeezed out by hand, the resulting moist material con- 

 tains 70 per cent as much chloride as sea water; when 

 metabolic water is added, the plankton appears to afford 

 sufficient water to permit the excretion of metabolic 

 products in a urine no more than four times as concen- 

 trated as the blood. The margin of available water is, 

 however, a narrow one. The fate of the ingested magne- 

 sium and sulfate is imdetermined. 



That the seal-like pattern of water conservation may 

 be remotely related to the carnivorous habit is suggested 

 by the fact that the dog shows a qualitatively similar but 

 quantitatively much less marked relation between pro- 

 tein diet and filtration rate {62, p. 470 f}, but it seems 

 more likely that the pattern in the seal is related to the 



