58 MOLLUSCA. 



and Montag.i stand acquitted. The former has given us 

 several good dissections, and the latter minute descriptions 

 of the testaceous animals. 



Whilst, in the preceding remarks, we have objected to all 

 arrangements taken exclusively from the characters of the 

 shell, we also disapprove of those systems founded exclu- 

 sively on the characters of the animal. By the former class 

 of methodists, the simplicity of nature is sacrificed to their 

 peculiar views, and, by the latter, practical utility is disre- 

 garded. Devoting their whole attention to the animal, the 

 later naturalists have overlooked the house in which it 

 resides ; the roof which shelters it from the blast ; and the 

 walls which guard it from its foes. The former observ- 

 ers possessed very limited views of nature, and erected 

 systems obviously artificial. To the systems of the latter, 

 the same objections will apply. Thus, for example, among 

 the univalves of Adanson, the families are formed from the 

 position of the eyes chiefly. That the black points which 

 we witness at the tips or at the base of the tentacula are 

 actually eyes, we readily admit ; but what influence have 

 these eyes on the habits of the animal ? or rather, does a 

 change of position of these organs occasion a corresponding 

 change in the habits of the animal ? Unless this is answered in 

 the affirmative, we must consider such characters as equally 

 artificial with any employed by Linnaeus or his followers, 

 since they have no relation to any of the primary functions 

 of life. 



The employment of characters taken exclusively from the 

 anrmal is attended with so many practical difficulties, that 

 it never can be introduced into general practice. If we find 

 a shell thrown ashore, the animal may be dead, or it may re- 

 fuse for a time to display its organs, and prevent us from 



