INTERNAL ANATOMY OF INSECTS. 167 
have the faculty of giving birth to young ones without 
having had any intercourse with the other sex. How 
are we to explain this most extraordinary fact ? Are. 
we to suppose with Bonnet that these insects are truly 
androgynous, as strictly uniting both sexes in one ? This 
supposition, however, is completely overturned by the 
circumstance, that there are actually male as well as 
female Aphides, and that these, as was first observed 
by Lyonet, are united towards the close of the summer 
in the usual manner a . The most likely supposition 
therefore is, that one conjunction of the sexes suffices 
for the impregnation of all the females that in a succes- 
sion of generations spring from that union. It is true 
that at the first view this supposition appears incredible, 
contradicting the general laws and course of nature in 
the production of animals. But the case of the hive-bee, 
stated above, in which a single intercourse with the 
male fertilizes all the eggs that are laid for the space of 
txvo years, and in the case of a common spider men- 
tioned by Audebert b , for many years, shows that the 
sperm preserves its vivifying powers unimpaired for a 
long period, indeed a longer period than is requisite for 
the impregnation of all the broods that a female Aphis 
can produce; and if immediate contact with the fluid be 
not necessary, who can say that this is impossible ? It 
is, however, one of those mysteries of the Creator that 
human intellect cannot fully penetrate. But this anomaly 
in nature is not wholly confined to the Aphides ; since 
Jurine has ascertained that the same thing takes place 
with Daphnia pennata Mull [Monoculus Pulex L.), one 
Reaum. vi. 552. h N. Diet. d'Hist. Nat. ii. 284. 
