DAPHNIAD^. 81 



ings without producing eggs, has again become pregnant ; 

 February 1st, young born. 



On the 5th December isolated a young Daphnia born 

 from an ephippium ; January 18th, it has given birth to 

 young; 19th, isolated two of these, both females; February 

 8th, both of these have given birth to young ; isolated two 

 of them. 



I Avas at this period obliged, from circumstances, to 

 suspend my observations ; but the above experiment is 

 sufficient to prove the fact, that the young born from an 

 ephippial egg produce young, which in their turn become 

 mothers without the intervention of the male. Accordina- 

 to Jurme, who has watched the act with great care, the 

 following is the manner in which copulation is effected. 

 When the male attacks the female for this purpose, he 

 springs upon her back, and gradually descends, till he 

 reaches the inferior edge of her shell, and finds himself in 

 a position where the open edges of the shell are opposed 

 to each other. He then introduces the antennae and first 

 pair of feet into the interior of her shell, and with them 

 embraces her feet. Thus fixed, he cm-ves up his tail so 

 as to touch the female, who at first is much agitated, but 

 after a little time pushes out her tail also. They touch 

 each other, and then they separate, the male at the time 

 of touching having been agitated with convulsive motions. 

 The eggs are first to be seen in the shape of small, round, 

 pellucid globules, which mark the situation of the ovaries 

 placed along the sides of the intestine. These soon lose 

 their transparency, become enlarged and continuous, and 

 form a dark mass on the outer edge of the intestine, 

 partly globular and partly elongated. The creature now 

 changes its covering, and shortly afterwards the eggs quit 

 the ovary, and take their place in a spherical form in the 

 open space on the back of the animal, where they remain 

 till the time of expulsion, quite free and unattached. At 

 first they are quite round, and appear to consist internally 

 of little globules, like air-globules. The shape then alters 

 a little, becoming oval, and the globules augment in 



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