A RECONNAISSANCE OF THE RELATION BETWEEN 



DESICCVrioN AND CARBOX DIOXIDE 



1'knnrCTIOX IN ANIMALS. 



G. T. CALDWELL. 



HULL ZOOLOGICAL LABORATORY. THE UNIVERSITY < >i ("HK'AGO AND THE BIOLOGICAL 



v OF THE UNIVERSITY 01 ARI/ 



I. INTRODUCTION. 



A fairly comprehensive review of the literature on the desic- 

 cation .t' animals reveals work largely of t\\ ;al types, (i) 



;tion on the behavior of the .mimul as shown 

 i'ouer (1906), Hennings (1907), Jacobs (1909), Breitenbecker 

 ( I'd i , Shelford (1913, I9i4a), Chenoweth (10.17 . \\V-se (1917), 

 Hamilton (1917), and Bodine (1923), ami ater content 



and the vital limits of desiccation of animal- a- determined by 

 Leemvenhoek (1701), Baker (1764), !> , Semper 



[88l), I >urig (1901), Babcock (1912). S.-hmidt [918), Bodine 

 (1921 , and Hall (1922). From the standpoint of pn.--il.K- physio- 

 i-al changes resulting from water lo-- - in animal-, little has 

 i ilouc and it is the purpose of this paper t<> point out cer- 

 tain definite relations between desiccation and the physiological 

 states of a limited number of species, as determined by the ex- 

 t Ti-t ion of , ;,lc. 



The \\ork has been made possible largely through the- kind 

 gestlons and helpful comments of lr. \\ . C. A1K .-. Thanks 

 al-oihic 1'r. I.. 11. Hyman for assistance in the collection and 

 identification of material. 



II. MATERIAL. 



M.m\ animals were -ried and rejected as un-uitahlc U-< ause of 

 the inabilit\- to keep them quiet throughout the determinations. 

 The material \\ a- >elei d so far as po->ible v. ith regard to the 

 natural habitat of the animals. The meal \\..rm, larva of 

 Tcncbrio inolitor Linn., a xerophilous animal, the larva of the 

 ei;Jit-spotted fore-ter moth, Alypia octoiuacul: . I abricius, a 

 mesohygrophilous animal, and the >luv;, Agriolimax campestris 



259 



