CYCLOPID.E. 195 



itself support ; it then, by moving its limbs and shaking 

 the valves of the shell, the new parts at the same time 

 coming forward, loosens the old covering, and in a short 

 time frees itself from the exuviae altogether, leaving behind 

 the sheaths of the limbs, hau*s, plumes, and even the minute 

 setulse, that almost escape the power of the microscope 

 itself from their fineness, such as the delicate plumose 

 setae which adorn the filaments of the tail. " How far 

 beyond all idea this most subtle fineness !" says Miiller, 

 from whom I have taken this description ; "for they are 

 sheaths containing other smaller sheaths, which again in- 

 clude other organs smaller still."* 



The number of times they moult during life is not 

 known ; but Jurine says, they ordinarily, though not 

 always, moult before each time of laying eggs. They cer- 

 tainly do not always do so ; and perhaps the frequency of 

 their moulting may depend much upon the temperature, 

 the season, &c. 



Having the experiments of Spallanzani and others, 

 upon the reproduction of mutilated members in various 

 animals, in his eye, M. Jurine instituted a series of expe- 

 riments upon the Ct/cloj)s quadricornis, to see how far this 

 power existed in this family. In his first attempts he 

 failed, the animals having died before they moulted, and 

 without showing any evident change in the mutilated 

 members. At length, however, he succeeded. He cut 

 off about two thirds of an antenna in a female, which 

 lived and moulted, reappearing after moulting, with 

 beautiful, perfect, new antennae, the old one of the cast 

 shell not having shown the least indication of a change, f 



Some authors have asserted that these insects possess a 

 wonderful power of resisting drought, and that when, by 

 reason of the summer heats, the marshes become dried up, 

 the little creatures do not die, but as soon as the mud is 

 again moistened by the rain, they recover entirely. Jurine 

 doubted this, and commenced a course of observations to 



* Entomost., p. 9. f Hist, des Monoc, p. 40. 



