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BRITISH ENTOMOSTRACA. 
tures.” Straus says he has frequently hatched the young 
from these ova by suddenly bringing them into a warm 
temperature. I have, by repeated experiments, ascer- 
tained the truth of Straus’s statement, and frequently 
witnessed the young hatched from these ephippial eggs, 
by keeping them in my room in a genial temperature. 
On the 2d of November I took several ephippia, which 
I found floating on the surface of a saucer full of water, 
containing numbers of D. pulex, many of which had 
ephippia attached to them, and placed them by themselves 
in a glass of clear water. On the 10th, two young ones 
were born ; 16th, one more born ; 29th, two more born ; 
21st, one more ; and 23d, two more born. 
November 29th, I took several ephippia from the same 
saucer as the last, and isolated them in the same manner. 
December 5th, three young ones are born ; 6th, two more ; 
8th, two more ; 10th, two more; and on the 16th, one 
more, were born. 
On the 19th of November I isolated a Daphnia, with 
the ephippium attached ; 21st, it has thrown off the 
ephippium ; December 5th, one young one is born from 
the ephippial eggs. I have repeatedly performed the 
same experiment, and have always found similar results. 
The young from these ephippial eggs do not differ from 
those born naturally, unless that they are perhaps a little 
longer in coming to maturity. 
In a young D. joulex, born naturally on the 8th of 
December, it moulted the first time on the 12th, or four 
days after birth ; on the 21st, or thirteen days after birth, 
it moulted for the fourth time, and had eggs ; whilst in a 
young one of the same species, born from an ephippial 
egg on the 5th December, the first moulting took place 
on the 13th, or not till eight days after birth ; and the 
fourth, when she had eggs, not till the 3d January, or 
twenty-nine days after birth. The periods between each 
moulting are also longer than in the others. 
It has been asserted, as I have mentioned above, by 
Jurine, that these ephippia are the consequences of a 
