124 COMPARATIVE ANATOMY. 



primitive plan, as in the several changes and accommoda- 

 tions which it is made to undergo." 



Very much of this reasoning is applicable to what has 

 been called Comparative Anatomy, In their general econ- 

 omy, in the outlines of the plan, in the construction as well 

 as offices of their principal parts, there exists, between all 

 large terrestrial animals, a close resemblance. In all life is 

 sustained, and the body nourished, by nearly the same ap- 

 paratus. The heart, the lungs, the stomach, the liver, the 

 kidneys, are much alike in all. The same fluid (for no 

 distinction of blood has been observed) circulates through 

 their vessels, and nearly in the same order. The same 

 cause, therefore, whatever that cause was, has been con- 

 cerned in the origin ; has governed the production of these 

 different animal forms. 



When we pass on to smaller animals, or to the inhabi- 

 tants of a different element, the resemblance becomes more 

 distant and more obscure, but still the plan accompanies 

 us. 



And, what we can never enough commend, and which it 

 is our business at present to exemplify, the plan is attend- 

 ed through all its varieties and deflections by subservien- 

 cies to special occasions and utilities. 



I, The covering of different animals (though whether I 

 am correct in classing this under their anatomy I don't 

 know) is the first thing which presents itself to our observa- 

 tion ; and is, in truth, both for its variety, and its suitable- 

 ness to their several natures, as much to be admired as any 

 part of their structure. We have bristles, hair, wool, furs, 

 feathers, quills, prickles, scales ; yet in this diversity both 

 of material and form, we cannot change one animal's coat 

 for another, without evidently changing it for the worse ; 

 taking care however to remark, that these coverings are in 

 many cases armour as well as clothing ; intended for pro- 

 tection as well as warmth. 



The human animal is the only one which is naked, and the 

 only one that can clothe itself. This is one of the proper- 

 ties which renders him an animal of all climates, and of 

 all seasons. He can adapt the warmth or lightness of his 

 covering to the temperature of his habitation. Had he 

 been born with a fleece upon his back, although he might 

 have been comforted by its warmth in high latitudes, it 

 would have oppressed him by its weight and heat as the 

 species spread towards the equator. 



