180 



PHYSIOLOGICAL KEGULATIONS 



tory organs are in some cases slower than rats, but unicellular ones 

 are faster. In recoveries, by intake, from water deficits (figs. 104 

 and 105) the contrasts are enormous. If in mammals absorptive 

 rates be substituted for ingestive rates, the diversities are scarcely 

 reduced. In aquatic invertebrates the body size is not the only 

 correlative of rate, since Bipalium is slower than some larger 

 species. 



Parenthetically, adjustments by water intake are further ana- 

 lyzed (table 15), the data happening to concern mammals. All 

 species are capable of extreme feats of drinking; how much they 

 drink appears to be graded to the deficits of water imposed. Just 



02 04 06 oa 



10 12 

 Hours 



Fig. 102. Course of relative water load (% of initial load) after recovery began 

 in diverse species of vertebrates that received 5 to 11% of Bo of excess water. Toad- 

 fish, young Opsantts tau, of 6.3 gm. kept in sea water at 23° C, at zero time injected in- 

 traperitoneally with 9.5% of Bq of distilled water; new data. Babbit, 7 individuals 

 of 1800 gm. each given 5.7% of Bq of water by stomach; data of Abe ('31a) ; see also 

 figure 72. Eat, 18 individuals of perhaps 250 gm. each given 5.0% of B„ of water by 

 stomach; data of Heller and Smirk ('32a, p. 15) ; see also figure 75. Snake, eight tests 

 on Thamnophis of 8 to 101 gm., given 10.9% of B„ of water by intraperitoneal injection; 

 data of figure 80. Dog, three tests on one individual of 13,870 gm., given 6.1% of Bo 

 of water by stomach; data of figure 1. 



as the initial rates of ingestion are directly correlated with - AW, 

 so several of the other measurements listed (duration of draft, rate 

 of swallowing) are found to be proportional to deficit. Among 

 species, many relations to body size are apparent. The frequency 

 of the gulps of which the drafts are composed is quite uniform, 

 and the size of each gulp is closely proportioned to body weight. 

 At one deficit the duration of initial drafts is roughly the same in 

 all species, and hence the rate of swallowing is proportional to body 

 weight. It may be said that the features of intake are geared to 



