ON THE AGAMIC REPRODUCTION AND MORPHOLOGY OF APHIS 31 
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 generations of similar females until the close of 
summer” (p. 235). 
It has not been my good fortune to discover, either in Professor 
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 :— 
“T am indebted to my friend Mr. Haliday for the following 
translation of an extract from Erichson’s Bericht, &c., 1844, Ent. 
Zeitung, pp. 9, 81, 133, 410. Ratzeburg observed a species of Aphis 
on the Birch, which continued to produce a living progeny from 
August into winter without either male or female appearing. Bouché 
and Kaltenbach, in explanation, remark that the males in this family 
are not always winged. However, in the May following, Ratzeburg, 
continuing his observations, found the winged females, and afterwards 
(in October) winged males also, which paired with them. The 
species was then identified as A. oblonga, Von Heyden. For the 
male to pair with a winged female (continues Mr. Walker) is a very 
unusual case among Afpfhides.”1 In fact, I have hitherto found, in 
Mr. Walker’s long list of 101 species, no case of an oviparous winged 
1 On turning to Ratzeburg’s notice in the ‘Entomologische Zeitung,’ 1844, p. 410 
(Fortgesetzte Beobachtungen iiber die Copula der Blattlause), which is the last word of the 
correspondence between Kaltenbach, Bouché and himself on this subject, I find his precise 
words to be these :—‘‘ Wie gross war daher mein Erstaunen, als ich bei meiner ersten, nach 
‘der Riickkehr angestellten Excursion, am 22 October gleich auf den ersten Blick unter der 
Menge von ungefliigelten Individuen, welche die des vorigen Jahres bei weitem iibertraf, 
auch gefliigelte Puppen und gefltigelte Mannchen bemerkte, und wie gross war meine Freude, 
auch gleich darauf mehrere der letztern in der Begattung zu finden, also in einem Acte, den 
ich bei Blattlausen selbst noch nicht hatte beobachten kénnen.” Subsequently, Ratzeburg 
states that he was able to observe the copulatory process early and late, at any time between 
the 22nd October and the 16th November. 
It will be observed that there is not a word here about such winged females as Ratzeburg, 
in a preceding passage, states he saw in May of the same year. The winged pupz are 
apparently, from the context, the pupze of the males, and the forms with which the winged 
males copulated were the wingless females. So that here, as in all other supposed cases of 
winged, oviparous true Aphides I have looked into, the evidence, when closely examined, 
breaks down. 
