383 Eelation of Watek to the Behavior of 



limiting factor in an arid region and the prime essential for metabolism, the 

 behavior of the potato beetle in a desert is determined chiefly by the water- 

 content of its environment. Henderson (1913) states: 



" Water, of its very nature, as it occurs automatically in the process of cosmic 

 evolution, is fit, with a fitness no less marvelous and varied than that fitness of 

 the organism which has been won by the process of adaptation in the course of 

 organic evolution, ... In truth, Darwinian fitness is a perfectly reciprocal 

 relationship. In the world of modern science a fit organism inhabits a fit 

 environment." 



These results upon the potato beetle indicate that its marvelous fitness and 

 adaptation to water is such a " reciprocal relationship." 



The experiments were performed at the Desert Laboratory of the Carnegie 

 Institution of Washington, and it is a pleasure to acknowledge my indebtedness 

 to its director, Dx. D. T. MacDougal, for his interest manifested. I must also 

 acknowledge my great indebtedness to Professor W. L. Tower, of the University 

 of Chicago, who made it possible for me to continue this problem at Tucson, 

 The following bibliography gives only the literature cited. 



BIBLIOGRAPHY. 



Abebhaxden and Hall. 1908. Text-book of physiological chemistry. Page 354. 



Adams, G. P. 1903. On the negative and positive phototropism of the earthworm, 

 Allolobophora foetida Say., as determined by light of different inten- 

 sities. Amer. Jour. Physiol., vol. 9, pp. 26-34. 



Allee, W. C. 1912. An experimental analysis of the relation between physiologi- 

 cal states and reotaxis in Isopoda. Jour. Exper. Zool., vol. 13, pp. 

 269-344. 



Babcock, S. M. 1912. Metabolic water : Its production and role in vital phenomena. 

 Univ. Wise. Agr. Exp. Sta. Research Bull. No. 22, pp. 87-181. 



Bachmetjew, p. 1902. Temperature of insects. American Nat., vol. 36, pp. 401- 

 405. 



Baker, F. C. 1911. The Lymnseidae of North and Middle America. Chicago Acad- 

 emy of Science, Special Pub. No. 3. 



Baumbekgeb, J. P. 1914. Studies in the longevity of insects. Annals Entom. Soc. 

 Amer., vol. 7, pp. 323-353. 



Bellion, M. 1909. Recherche experimentale sur I'hibernation I'escargot. Ann. 

 Univ. Lyon, ser. 27. 



Bbeitenbecheb, J. K. 1911. The hibernation of a desert beetle (Leptinotarsa decern- 

 lineata Say). Year Book Carnegie Inst. Wash., No. 10, p. 55. 



. 1912. The water-content and activity of animal organisms. Year Book Car- 

 negie Inst. Wash., No. 11, pp. 71-72. 



Brudin, M. T. 1913. Light reactions of terrestrial amphipods. Jour. Animal 

 Behav., vol. 3, pp. 334-352. 



Chenoweth, H. E. 1917. The reactions of certain moist-forest mammals to air 

 conditions and its bearing on mammalian distribution. Biol. Bull., vol. 

 32, pp. 220-227. 



Child, C. M. 1910. Analysis of form regulation with the aid of anesthetics. Biol. 

 Bull., vol. 18, pp. 161-173. 



Cole, W. H, 1917. The reactions of Drosophila ampelophila Loew to gravity, centrif- 

 ugation, and air-currents. Jour. Animal Behav., vol. 7, pp. 71-81. 



Davenport, C. B. 1897. The role of water in growth. Proc. Bos. Soc. His., vol. 28. 



Dice, L. R. 1914. The factors determining the vertical movements of Daphnia. 

 Jour. Animal Behav., vol. 4, pp. 229-265. 



EsTABBOOK, A. H. 1910. Effect of chemicals on growth in Paramoscium. Jour. 

 Exper. Zool., vol. 8, pp. 489-535. 



FtJLLER, G. D. 1911. Evaporation and plant succession. Bot. Gaz., vol. 52, pp. 195- 

 208. 



Gbeely, a, W. 1901. An analogy between the effects of loss of water and lowering 

 of temperature. Amer. Jour. Physiol., vol. 6, pp. 122-129. 



