their Respiration. 115 



16 miles west of Utica, the workmen found several hundred 

 of live molluscous animals. They were chiefly of the Mya. 

 cariosa and Mya purpi^rea. The workmen took the animals, 

 fried, and ate them. He adds, ' I was assured that they were 

 taken alive ^2ft. deep in the deposit. Several of the shells 

 are now before me. The deposit is diluvial. These animals 

 must have been there from the time of the deluge, for the 

 earth in which they were is too compact for them to have been 

 produced by a succession of generations. These freshwater 

 clams of 3000 years old precisely resemble the same species 

 which now inhabit the fresh waters of that district ; therefore, 

 the lives of these animals have been greatly prolonged by 

 their exclusion from air and light for more than 3000 years." 

 (Silliman's Amer. Journal^ No. xv. p. 249., as quoted in Tur- 

 ner's Sacred History, p. 473.) 



With the exception of the last example, the others refer to 

 land Testacea ; but some pulmoniferous aquatic species are 

 equally capable of assuming this state of torpidity, when under 

 circumstances which deprive them of their respiratory medium. 

 In early spring, I have more than once observed the Limneus 

 fossarius to abound in small pools of water, which were dried 

 up as the season advanced ; and when, after a careful search, 

 the little snails were found, in a torpid condition, concealed 

 in the cracks made by the drought, or under small clods of 

 earth, where they awaited a happier season to refill their pools, 

 and permit them to resume the functions of active life. Per- 

 haps, in this country, their torpidity can rarely be continued 

 beyond a few weeks ; but, in tropical climes, similar species 

 can pass the dry season of five long months in this state. 

 Thus, Adanson informs us that the minute freshwater shell, 

 which he calls Bulimus, is to be seen only from the month of 

 September to January, in the marshes of Senegal, formed by 

 the rains which fall in June, July, August, and September. 

 When these marshes are dried up, and, as it were, roasted by 

 the sun, the shellfish disappear; a few empty shells alone 

 being left, to show where they had been ; but they never fail 

 to return with the rainy season ; and Adanson remarked that, 

 the hotter the preceding summer, the more abundant was the 

 issue of the succeeding hordes. How, asks the author, shall 

 we explain this marvellous reproduction ? Can the eggs of 

 the animal, necessarily very delicate and minute; can they 

 remain in a soil so burned up, without being entirely dried; or 

 can the animals themselves, if it is true that they conceal 

 themselves in the bosom of the earth, can they resist, during 

 five or six months, the heat of a burning sun ? {Hist. Nat. 



i. 2 



