254 History of Conchology. 



peu contribue a augmenter leur dedain. lis se sont done bornes'a 

 I'examen des coquilles, ils n'en ont considere que le forme, celle de 

 son ouverture, on le nombre de ses pieces ; c'est d'elle seule qu'ils 

 ont voulu tirer leurs caracteres primitifs et distinctifs : de-la cette 

 foule de systemes aussi peu satisfaisans les uns que les autres."* 



At a season when ' Systems' were all in vogue Adanson, with 

 characteristic boldness, declared himself their enemy as being worse 

 than useless, fit only to amuse triflers, certain to lead to error and 

 alienate us from true views of the objects in question, and so easy of 

 invention to boot that several equally good might be made by one 

 of common experience and capacity. The history of conchology 

 had already offered too many examples of the truth of this assertion, 

 and he was not slack to give additional specimens in its illustration. 

 But notwithstanding his philippick against them, Adanson, in some 

 measure, forgot his own principles, and was little less of a systema- 

 tist than those were whom he censured. Shell-fish were, according 

 to him, distinguishable in the first place into " Lima9ons" and " Con- 

 ques ;" the former were subdivided into univalves and operculated 

 univalves, and the Conques into bivalves and multivalves ; these 

 primary families were still further divided into smaller groups from 

 the position of the eyes in the Lima9ons, and from the figure of the 

 respiratory tubes in the Conques. Now it was a pure arbitrariness 

 in him to fix upon the operculum as apart or organ of primary value, 

 for there is nothing in its use or position to justify the choice, nor 

 did he attempt, by any analysis, to show that it was a regulator of 

 structure and habits ; and it was equally arbitrary to divide the bi- 

 valves into two sections on the mere existence of a few additional 

 pieces over the hinge, for these pieces were not proved to be an index 

 to the animal's economy. But A.danson's services to conchology are 

 very great, — of those its labourei's who have passed in review we place 

 him next to Lister. He has the merit of having altogether remov- 

 ed from the Testacea the Lepas and Balani, whose structure he saw 

 was modelled after the type of another category ; his interesting dis- 

 covery of the Vermetus was a fine illustration of the shell being of 

 itself useless as a character in natural history ; and his knowledge of 

 affinities was made evident by the acuteness which lead him to ap- 

 proximate the Teredo to the Pholas. If not the first to point out 

 the importance of the operculum, he was undoubtedly the first who 

 knew its value as an index to natural relationship between genera ; 

 perhaps the first who was fully aware that the entireness or canali- 



* Hist, des Coqiiillages, pref. v. 



