DAPHNIADiE. 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 was 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. According 
to Jurine, 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 curves 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 
6 
