HEAT 



317 



acquire a moderate reserve of available augmentation in heat pro- 

 duction which assists in compensating negative heat loads. But 

 even in adults the range of "chemical regulation" is an augmenta- 

 tion ratio of less than 2. Loss, therefore, is the more flexible in 

 rabbit as well as in man. 



Although rabbits with positive heat loads were studied to some 

 extent (Terroine and Trautman, '27; Mayer and Nichita, '29), the 

 periods of measurement were too long to allow accurate correlation 

 of heat exchanges with heat loads during recovery. Both heat pro- 



3 



o 



X. 



a. 



16 - 



12 



8 = 









Rabbif , 



4— 



6 



B 



4 ^-^ --^^^ 



\Z 



C 



26 

 D 



& 



0^ 



" 34 



Adul-l- F 



yAdullG J^- 



I -r=^<r^ 



'-%^=^^'0...-=:r± 



23 



!> 



-12 



-10 



-8 



-6 



-4 



-2 







Hea+ Load 

 Fig. 151. Eate of heat production (Cal.Ag- hr-) in relation to heat load (Cal.Ag.) 

 in rabbits of diverse ages. Each point represents several individuals that cooled during 

 the 2 to 3 hours required for the measurement of oxygen consumption, except in group 

 Gr where rewarming was proceeding. Points are roughly connected in successive age 

 groups designated A to F. Ages are numbered in days after birth; from data of Ging- 

 linger and Kayser ('29, p. 740). Additional adult curve (G) from figure 149 (data of 

 Gasnier and Mayer, '35). Horizontal lines indicate range of heat loads prevailing 

 during the measurements, as computed from rectal temperatures (T°) alone; (T°-39°) 

 xO.83, 



duction and heat loss are augmented in heat excesses brought about 

 by confinement in warm air. 



Thus, although the turnover of heat in rabbit is thrice as rapid 

 as in man, no marked differences are known in the variability of 

 heat content and of heat exchanges, nor in the modifications of heat 

 exchanges in the presence of heat loads. But in rabbit variations 



