334 STUDIES OF NATURE. 



two eyes, can take in, at once, more than half of 

 the Horizon ; with a lingle one, he could fcarcely 

 have embraced a third part. Provided with two 

 arms, he can perform an infinite number of ac- 

 tions which he never could have accompliflied with 

 one only ; fuch as raifing upon his head a load of 

 confiderable fize and weight, and clambering up a 

 tree. Had he been placed upon one leg, not only 

 would his pofition be much more unfteady than 

 upon two, but he would be unable to walk ; his 

 progreflive motion would be reduced to crawling, 

 or hopping. This method of advancing would 

 be entirely difcordant to the conflitution of the 

 other parts of his body, and to the variety of foils 

 over which he is deftined to move. 



If Nature has given 3, fingle exterior organ to 

 animals, fuch as the tail, it is becaufe the ufe of 

 it, being extremely limited, extends but to a fingle 

 aélion to which it is fully equivalent. Befides, the 

 tail, from it's fituation, is fecured againfl almoft 

 every danger. Farther, hardly any but the very 

 powerful animals have a long tail, as bulls, horfes, 

 and lions. Rabbits and hares have it very fhorr. 

 In feeble animals, which have one of confiderable 

 length, as the thornback, it is armed with prickles, 

 or elfe it grows again, if it happens to be torn off 

 by an accident, as in the cafe of the lizard. Fi- 

 nally, 



