ADAPTATIONS TO TROPICS AND ALTITUDES 



In summary, the chiroptera also show a variety of responses. 

 Traditionally the insectivorous species are characterized by their 

 thermolability, but the behavior of some of the frugivorous species 

 can be indistinguishable from other mammals. However, even in 

 the larger bats scattered values suggest a latent thermolability 

 which may be manifested under appropriate conditions. But since 

 this thermolability, either expressed or latent, appears to be suited 

 to the environmental and metabolic needs, we should hesitate to 

 describe it as a primitive feature or an inadequacy. 



Primates 



The last group to be considered is an advanced one, but with 

 one exception, is even more strictly limited to the tropics. There 

 is considerable T data on the Primates partly because of their 

 use as laboratory animals, but also because of tuberculin testing, 

 particularly at the Philadelphia Zoological Garden, (Brown, 1909; 

 Fox, 1923). Some recent data are shown in Figure 16 which compare 

 four species of Cebus and shows the extreme regularity of their 

 response. The temperature cycle with an amplitude of 2.5 C is 

 substantial, but not extreme. 



Figure 17 represents a smaller primate, the marmoset 

 (Callithrix) J which shows a striking diurnal cycle with an amplitude 

 of almost 4.0 C. Although these animals adapt well to handling 

 and have been popular as pets for more than a century, there is 

 almost no physiological information on them. Figure 18 considers 

 another marmoset which is of interest as the smallest of the pri- 

 mates and weighs about 100 g. It, too, has a very striking cycle, 

 although not so large as Callithrix . A unique feature is the minimum, 

 which is very low for a primate. One may wonder if the cryptorchid 

 condition sometimes reported in this genus (Hill, 1959) depends on 

 this low body temperature, in accordance with the general relation 

 between body temperature and descent of the testes as discussed by 

 Wislocki (1933). Figure 19 shows the effect of limiting temperature 

 measurements to six fixed times during the day as has been done 

 in many measurements on Primates. A substantialdistortion results 

 with a plurring of the almost "square" wave form seen in Cebuella 

 and a loss of resolution of secondary waves. 



405 



