BONNET. 
51 
wards attempts to explain that these tumours arise 
through the law that soft bodies under pressure, 
like liquids, rush to the points of least resistance. 
Accordingly, he attributes the tortuous bending of 
such leaf-structures, and their singular modifica- 
tions into bladders, &c., to the effects of insect punc- 
ture and irritation, which causes the exudation of 
the softer parts.* Bonnet gives a lively descrip- 
tion of the attacks made on Aphides by their nume- 
rous foes. He commences with the larva of the 
mange pucer on (Syrphus), which, seated on a leaf or 
twig, transfixes and cuts with its trident-armed head 
into its helpless prey, so that, he says, in nature perhaps 
there is no animal carnacier qui chasse avec plus 
d’avantage.’’ He then goes on to notice the voracity 
(previously observed by Reaumur) of Ze lion des 
pucerons ” (Hemerobius), and also the insatiable appe- 
tite of la vache d Dieu^^ or ^^bete de la Vierge’^ 
(Coccinella). Even le petit ver que le puceron 
nourrit dans son interieur, et qui lui donne la mort ” 
(Aphidius), does not escape his observation. He winds 
up his remarks on these enemies by observing, Like 
as we* sow grain to provide for our own subsistence, so 
it appears that nature sows ^ les pucerons,’ on all kinds 
of trees and plants, for the nourishment of multitudes 
of different insects.” 
Subsequently Bonnet enters upon the most impor- 
tant part of his work on Aphides, viz. their peculiar 
mode of reproduction. He refuses to discuss the 
opinion of the old philosophers, who maintained that 
Aphides were engendered of the dew, or to argue upon 
the before-mentioned notion of Goedaert, who pre- 
tended that they spring from the moist semence'^ 
deposited by ants. Bonnet, to put an end to mere 
* Bonnet is by no means so happy as Reaumur in his explanations 
of how these monstrosities are produced. The latter author gives many 
interesting plates, showing how helical curves andvasiform masses may 
be produced through the continued punctuation of normal vegetable 
growths. Bonnet is indebted to Reaumur for many of his remarks, and 
also for most of the figures of his memoir on Aphides. 
