ORGANIC AND INORGANIC MATTER COMPARED. 83 



insinuates itself into every crevice, conforms to 

 its superficies, and cements the first layer of 

 the internal skeleton to the substratum on 

 ■which it is deposited, and from which it must 

 be broken off. We are here reminded of the 

 growth of the antlers of the stag or fallow deer ; 

 the burr of which is rooted on the skull, and 

 the stem and branches of which are secreted 

 by a velvet-covered skin, which in due time 

 perishes. There is, however, this difference ; 

 the velvet of the antlers is a peculiar and tem- 

 porary development of the skin of the animal, 

 in order to effect a given object. In these fan- 

 like, or frond-like zoophytes, the investing and 

 secreting rind, or integument, results from the 

 development of a minute germ, alien to the 

 rock or stone on which it chances to fix. Yet 

 the analogy between the growth of a fan-like 

 zoophyte and the antlers of the deer is very 

 striking, and a consideration of the process in 

 the latter case will lead the reflective mind to 

 form a clear idea of the process in the former ; 

 only that in the case of the zoophyte, secretion 

 of horny or calcareous matter is not carried on 

 by the agency of distinct and palpable blood- 

 vessels. 



To revert to plants. There are many spe- 

 cies which never bear flowers — never exhibit a 

 calyx, petals, stamens, or pistils, and yet mul- 

 tiply by prolific seeds. We may here instance 

 the ferns. In these plants the seeds are arranged 

 at the back of the fronds, either near the sum- 

 mit or at the base ; and this fructification is 



