INTERNAL ANATOMY OF INSECTS. 161 
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 
Jemale Aphides, and that these, as was first observed 
by Lyonnet, are united towards the close of the sum- 
mer in the usual manner*. ‘The most likely supposi- 
tion therefore is, that one conjunction of the sexes suf- 
fices for the impregnation of all the females that in a 
succession of generations spring from that union. It is 
true that at the first view this supposition appears incre- 
dible, contradicting the general laws and course of na- 
ture 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 two years, and in the case of a common spider men- 
tioned by Audebert>, 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 Ju- 
rine has ascertained that the same thing takes place with 
Daphnia pennata Mull (Monoculus Pulex L.), one of 
Branchiopod Crustacea‘. It is worth observing whether 
© Toid. on2. > WN. Dict. d’ Hist. Nat. ii. 284. 
¢ Jbid. ix. 125. Bonnet and Jurine both found that the female 
Aphides and Branchiopods that were fertile without the usual inter- 
course of the sexes were less fruitful than their mother, and those 
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