61 



which many hairs present, viz. such as are represented in figs. 16 & 17, 

 if it were found that the shaft of the hair grew faster than the scales 

 which surround it, and that the whorls of scales were separated from 

 each other just as the slides are in the drawing out of a telescope. 



Since these observations were made I have been kindly favoured by 

 Mr. Powell with some hair of a bat from India, the species of which 

 is at present unknown, in which the view I have entertained of the 

 nature of bats' hair is beautifully borne out, and if any doubt had 

 previously existed of the scaly character, I think that it would at 

 once be banished when these hairs were seen under the microscope. 

 The scales are most remarkably developed, and in some of the hairs 

 they surround the shaft in a continuous whorl ; and without any prepa- 

 ration by scraping, in many places they will be found to be entirely 

 wanting ( fig. 18 ), whilst in others they are still attached to the 

 shaft, but out of their proper position (fig. 18, a). 



Physiologists have been long agreed that hair and feathers are 

 constituted upon one uniform plan, but as yet there have been many 

 links wanting to complete the chain of evidence upon which this 

 analogy is maintained. The hair of the animals in question will 

 certainly supply the links to a certain extent, and as the zoologist 

 would tell us that they resemble quadrupeds principally in their 

 mode of reproduction, and birds in their mode of progression, so 

 the microscopic observer now can say that they resemble both in 

 the structure of their hair. 



