196 PROF. HUXLEY ON THE AGAMIC REPRODUCTION 
antennæ. It was only in November that the apterous females presented eggs in their 
ovaries and oviducts, and for that effect, a considerable degree of cold was necessary*.” 
Morren describes the male, female, and agamic organs of reproduction, but less com- 
pletely than Von Siebold, who, in 18397, carefully investigated the Aphis Lonicere, and — 
first demonstrated the existence of the spermatheca and colleterial glands in the oviparous 
females. Von Siebold distinguishes three forms of this species, two winged and one 
apterous. The large winged Aphides were all viviparous; the smaller, males. The 
apterous forms were oviparous, and the progeny of the alate females. 
Steenstrup says of the Aphides (Alternation of Generations, p. 108), * The propagation 
of these creatures through a series of generations. has been already long known, In the 
spring, for instance, a generation is produced from the ova, which grows and is metamor- 
phosed, and without previous fertilization gives birth to a new generation, and this again 
to a third, and so on for ten or twelve weeks; so that in certain species even as many as 
nine such preliminary generations will have been observed; but at last there always 
occurs a generation consisting of males and females, the former of which after their meta- 
morphosis are usually winged; fertilization and the depositing of eggs take place, and 
the long series of generations recommences in the next year and in the same order.” 
In the first edition of Professor Owen’s ‘ Lectures on the Invertebrata,’ published in 
1843, however, Morren’s errors are adopted, extended, and enunciated as the law of pro- 
pagation of the Aphides, in the following terms :— 
* In the last generation, which is the seventh, the ninth, or the eleventh, according 
to the species of Aphis, the fertilizing influence would seem to have expired}, and deve- 
lopmental force exhausts itself in more frequent and numerous moultings, in the for- 
mation of wings, and in the modification of the female organs already described. Many 
males, which, like the females, acquire wings, form part of the produce of the last brood, 
which takes place in autumn. They rise in the air, frequently migrate in incalculable 
numbers, unite, and the females then produce eggs, which are glued to twigs and leaf- 
stalks, retain their vitality throughout the winter, are hatched in the spring, and give 
birth to the apterous and larviparous females, which continue to produce successive gene- 
rations of similar females until the close of summer.” (p. 235.) d 
It has not been my good fortune to discover, either in Prof. Owen's writings or those of 
his predecessors, any evidence in support of the singular statement contained in the last 
paragraph of this citation, which is incorrect in all important respects, and has, indeed, 
been omitted in the second edition of the * Lectures.’ 
Mr. Walker, in the first of his long and valuable series of papers on the Aphides 
(Annals, vol. i. 1848, p. 259), writes thus :— 
* “Or chez le puceron du pêcher j'ai vu un grand nombre de fois, et j'ai montré le phénomène à mon collègue, 
M. Burgraeve, que la femelle ailée et propre à la fécondation ne renfermait point des œufs et n'en pondait point, 
mais qu'elle renfermait des petits pucerons vivants qui naissent tout développés avec leurs pattes, leur trompe, et leurs 
antennes. Ce ne fut qu'en Novembre que les femelles sans ailes présentaient des ceufs dans les ovaries et les oviductes, 
et pour cela il fallait un froid déjà assez vif.”—Morren, l. c. p. 76. - 
$ Ueber die inneren Geschlechtswerkzeuge der viviparen und oviparen Blattlåuse. Froriep’s Neue Notizen, 1839. 
1 This phrase is little more than a translation of a passage in Morren which will be given below. 
