196 
BRITISH ENTOMOSTRACA. 
prove that they have not this faculty. He selected twelve 
of the Cyclops quadricornis , removed them out of the 
water, and allowed them to remain fifteen minutes dry ; 
seven of them he found to be irrecoverably dead ; the re- 
maining five revived. Again, he selected twelve others, 
and allowed them to remain twenty minutes dry ; eleven 
out of the twelve died. A third time he selected twelve, 
and after exposing them to the air in a dry state for twenty- 
five minutes, he found that all had perished.* 
These experiments, notwithstanding, are not quite con- 
clusive, for the mud in which they are enveloped, and in 
which they are very gradually dried, while in their native 
habitats, might retain a certain degree of moisture suf- 
ficient to prevent life being utterly extinguished; and 
I have accordingly found, upon examining ponds which 
had been filled again by the rain after remaining two 
months dry, numerous specimens of the Cyclops quadri- 
cornis in all stages of growth. Their power of resisting 
the action of cold, however, according to Muller, is much 
greater than their power of defying drought. In an 
experiment which he details, he says that he exposed 
some individuals of the Cyclops quadricornis , in a glass 
vessel, to a freezing air, and that when fully frozen, he 
continued the exposure for twenty-four hours. At the 
end of that time he placed the vessel containing their 
frozen bodies in a warm bath, watching the effect of this 
upon them frequently during the succeeding twenty-four 
hours, but without seeing any motion. Next morning, 
however, upon looking into the vessel, he observed, not 
without wonder, the insects alive, and swimming about as 
before congelation, the females with their bags of eggs 
adhering to them as usual ;f but although they did not all 
recover, the greater part were restored to life. 
In some other similar experiments upon these little 
creatures, throwing them into a state of asphyxia by 
means of spirits of wine, and then restoring them to life 
* P. 39. 
t Entomost., pp. 5, 6. 
