Chi the Flight of Aphis Per ska*. 189 



of Belgium were visited by a kind of hurricane, in which was 

 conveyed a host of small insects belonging to the species Aphis 

 persicat. The emigration appeared to commence between Bruges 

 and Gand, and from this place, as a centre, extended to the 

 north, the east, and the south. It is attributed by the author, 

 not to the appearance of the cholera, as had been pretended, but 

 to the extreme drought of the season, as it was also promoted 

 by the prodigious fecundity of the females, and the rapidity of 

 procreation, a single individual being able, as early as the second 

 conception, to produce not less than 10,000. It is the anatomical 

 structure which has especially excited the attention of M. Mor- 

 ren, so that, if possible, he might detect how it happens that the 

 females in this genus will produce their young ten or eleven 

 successive times, without intercourse with the male. 



M. Morren states that he has discovered a very simple diges- 

 tive canal, without any salivary or biliary vessels. Upon the 

 inferior wings he has discovered a hook which unites these with 

 the superior ones, The generative apparatus of the male is 

 composed of four or five testiculi, inclosing spermatic animal- 

 cules. The conducting canal is supplied with a large vesicula 

 seminalis, much larger than any author has pointed out as be- 

 longing to the Aphidiens. The corresponding apparatus in the 

 female is formed of an ovary of eight ovi or fwti-gerens sheaths, 

 according to the season. These sheaths have each three or four 

 apartments, where the young are gradually developed, and M, 

 Morren describes and represents all these transformations. When 

 in the condition of eggs, they are seen in the terminating apart- 

 ments. There is no sebific gland. Thus the animal is not her- 

 maphrodite ; and it will not be supposed to be the product of 

 spontaneous generation ; whilst it was not previously known 

 that the influence cf the male could be transmitted through ten 

 or eleven successive births. M. Morren, accordingly, believes 

 that there is an individualization of organized matter in the in- 

 dividuals who possess the construction of this species; and this 

 amounts to a kind of e quivocal generation. The small scales on 

 the abdomen of the Aphis, which help in the secretion of a sac- 

 charine matter, which the ants lick off, form also a part of the 

 respiratory apparatus, at the same time that they lead to parti- 

 cular glands. This fluid is the nourishment of the young ones 



