66 
BRITISH APHIDES. 
the purport of which was to prove that the oval bodies 
glued to certain plants in autumn and winter were the 
true ova of Aphides, and not, as had been stoutly main- 
tained by others, modified pupse. He set the matter at 
rest by a microscopic examination, through which he 
established the fact that, like all true ova, these 
bodies contained a voluminous yolk and a germinal 
vesicle. 
But the most important additions to our knowledge 
of the reproduction of Aphis made in this country are 
embodied in two elaborate memoirs written by Prof. 
Huxley* in 1858. These papers threw new light on the 
development of the true ova, and of those bodies which 
he styles the pseudova, organisms which are elaborated 
from the ovarian chambers of the oviparous and the 
viviparous females respectively. These memoirs con- 
tain descriptions and good plates of the internal repro- 
ductive female organs. Mr. Huxley, in concluding 
these memoirs, points out that there is a close corre- 
spondence in all essential respects as regards the 
embryonic phenomena in the three orders of insects, 
viz. the Hemiptera, the Diptera, and the Heuroptera. 
Again, Dr. Allen Thomsonf introduces remarks at 
some length on the formation of the ovum of Aphis 
into his article Ovum in Todd’s ^ Cyclopcedia of 
Anatomy and Physiology.’ The same subject is dis- 
cussed by Prof. Owen, both in his lectures on the 
Invertebrata and in his well-known work on Partheno- 
genesis. The last author’s views were also put into a 
condensed form in a lecture read to the members of 
the Royal Institution.:!: 
The embryology of Aphides is discussed also in the 
able memoirs and treatises of Von Siebold, Leuckart, 
Brandt, Claus, Olaparede, Mecznikow, Leon Dufour, 
and others. 
* Huxley, ‘ Linn. Trans.,’ voL xxii, pp. 193-221, “ On the Organic < 
Heproduction of Aphis.” 
t Vide article “ Ovum ” in the Supplement, pp. 34 and 113. 
t ‘ Proceedings of the Royal Institution/ vol. i, p. 9. 
