CYPRID.E. 149 



of fresh water, and are to be found in every pond and 

 ditch where the water remains stagnant, but not putrid. 



They are not so prolific as the Cyclopidce, but in some 

 of the larger species we can count sometimes, according 

 to Jurine, as many as twenty-four eggs. The males 

 have never yet been discovered, and the act of copu- 

 lation has never been witnessed by any author, with 

 the exception of Ledermiiller, who says he has seen them 

 in the act, and gives a representation of them in that 

 state. I have frequently witnessed two individuals in 

 much the same situation as those figured by Ledermiiller, 

 but it did not appear to me that they were at the time 

 engaged in copulation ; and as neither Miiller, De Geer, 

 Jurine, nor Straus have ever witnessed them in the act, 

 Ledermiiller must in all probability have mistaken the 

 nature of their junction. Straus states that every spe- 

 cimen he has examined has been laden with eggs, which 

 makes him ask, " Are they hermaphrodites ? or do the 

 males only appear at some particular season of the year?" 



Jurine has collected eggs immediately after they had 

 been deposited by the parent animal, has isolated them, 

 and seen them safely hatched. He has then isolated the 

 young after they were hatched, and found that they 

 became pregnant without the intervention of the male. 

 They must either, therefore, be hermaphrodites, or, as in 

 the Daphniadse, one copulation suffices not only to im- 

 pregnate the female for life, but the succeeding genera- 

 tions also ; as the males of the Daphniadse, too, appear only 

 at particular seasons of the year, and in small numbers, 

 it is probable that the males of the Cypridae will be found 

 hereafter by succeeding observers. The eggs are perfectly 

 spherical, and are deposited by the animal upon some solid 

 body, such as part of a plant, &c., in a mass, which at 

 times, says Straus, consists of some hundreds from various 

 individuals, the mother fixing them to the surface of the 

 body on which they are deposited, by means of a glutinous 

 kind of substance, and then leaving them. When the 

 animal is about to lay, it fixes itself, says Jurine, so firmly 



