86 CLASS MAMMALIA. 



an ample and compacted brain ; and the cranium composed 

 of a similar number of pieces equally convoluted. Their 

 sensitive, digestive, and secretive systems are similar. The 

 teeth of three sorts, the body equally covered with hair, 

 and they are viviparous and mammiferous. Their bones, 

 their muscles, their vessels, are all upon the same construc- 

 tion as in the quadrupeds in general, and the resemblance 

 is so great that the minutest details of their structure would 

 suffice solely and separately to shew that they are true 

 mammalia, and must be comprehended in that class. 



Far, however, beyond a result like this were the bold 

 views of Linnaeus, who ranged them unhesitatingly in the 

 same order with man and monkeys, giving to both a similar 

 name : sometimes that of Anthropomorphce (beings with a 

 human visage) ; sometimes that of Primates (animals of the 

 foremost rank in creation). Extraordinary as this classifi- 

 cation may appear, it has been consecrated by the illustri- 

 ous name of its inventor. 



A new school followed, which admitted among all living 

 beings certain successive and graduated relations, and a 

 progressive advance from the simple to the composite. The 

 case of the bats, constituted like the mammalia, but hover- 

 ing in the air like birds, furnished an example of transition 

 from one class to another too tempting not to be eagerly 

 adopted. But the faculty of flight in birds and in bats re- 

 sults from a very different mode of organization, and to 

 establish a relation between them from the circumstance of 

 both being sustained in the air, is to confound the effect 

 with the cause. This is produced in each by very different 

 instruments, and the anomaly which this faculty presents in 

 the cheiroptera is clearly derived from the type of the 

 mammalia. 



The parts which correspond to fingers are in birds very 

 nearly effaced. They exist only in a rudimentary state, 

 attenuated and sown as it were together. The hand of a 



