TEMPERATURE. 11 



easily preserved, and all its functions regularly performed. 

 We do not mean to intimate, that there is any animal which 

 can live in our climate, for example, and remain iminflucn- 

 ced by a difference of temperature of upwards of twenty 

 degrees between summer and winter. The constitutional 

 arrangement suited to the one season, would be prejudicial 

 during the continuance of the other. But there are many 

 animals which live in the same district both in summer and 

 winter, and even in districts differing considerably in their 

 mean annual temperature. What, then, are the means 

 employed by these species to preserve life in the midst of 

 such vicissitudes ? The power of producing heat or cold, 

 is a property obviously possessed by the warm-blooded ani- 

 mals, and probably in an inferior degree by those which 

 are termed cold-blooded. But in all the efforts made by 

 the system to secrete extraordinary degrees of either heat or 

 cold, tliere is so great a portion of vital energy expended,, 

 that exhaustion and death follow its long continuance. In 

 all cases where the influence of the seasons are to be resisted 

 by efforts of this kind, it v\rould be requisite to continue them 

 uninterrupted for many months. These efforts, however, 

 are diminished in extent and duration by a variety of the 

 most wonderful arrangements, exhibiting the infinite re- 

 sources of that Wisdom which planned the constitution and 

 continuance of the animal kingdom. To the chief of these 

 compensating or counteracting circumstances we shall now 

 briefly advert. 



1. Changes take place in the Quantity of the Clothing. — 

 The same circumstances which enable the Negro to go about 

 in a state approaching to nakedness, and impel the inhabi- 

 tants of the arctic regions to cover themselves with woollen 

 cloth or skins, operate in regidating the clothing of quad- 

 rupeds and birds. In the warmer regions, it is requisite to 

 suffer the temperature of the Body to be diminished, Avhile, 



