62 LINNEAN SYSTEM. 



Genus 46. Cimex. 



Jioslrutn inflected: antenna: lonsier than llio thorax: uhtss four, folded 



crosswise; tlie upper ones coriaceous in tii;; anterior pari: buck flat : 



tliorav marginated : _/eef formed for running. {PI. 5. Jig. 6, 7, 8.) 



The insects of this genus, whetlier as hirva' or in the perfect state, 



feed for the most part on the juices of plants; some on the larvre of 



other animals: they have in general a very disagreeahle smell. The 



larvas and pupaj have six feet; they are active, and walk ahout like the 



perfect insect: the former has no wings, the latter has the rudiments 



of them. A great numticr oi' species arc found in Britain. 



Sp. 1. Cimex kctularius. Without wings, 

 lidiahils Europe. 



This insect (the hed-bug) is unhappily but too well known, and was 

 an inhabitant of Europe prior to the Christian a'ra; at least it is men- 

 tioned by Aristophan(!S and other (jreek writers. Southall says it was 

 hardly known in London before 1070; but there is good authority for 

 asserting that it was common enough there before t?ie great fire in 

 1666. It is a nocturnal animal, very fetid ; seldom, though sometimes, 

 found with wings; easily killed when taken alive. Bugs arc said to be 

 expelled in a variety of ways, viz. by charcoal and oil of turpentine, soft 

 soap, or hard pomatum. 



Genus 47. Aphis. 



Rostrum inflected: the vagina with five articulations and a single seta: 

 a«toi/i<Pselaceous, longer than the thorax: ninga four, erect, or none: 

 feet formed for walking : the abdomen generally armed with two horns. 

 \Pl.^.f,g.9.) ^ 



The insects of this genus are small and defenceless; but very nox- 

 ious animals, and most remarkable for the singularities in their history 

 and manners. They seldom a])pear before autumn, when the males im- 

 jiregnate their females, which soon thereafter lay eggs or rather a sort of 

 capsule in which the young Aphides lie alreiuly perfectly formed, but 

 do not break their shell till the following spring. When they appear, 

 it is very remarkable that they are almost wholly females, with hardly 

 a male to be seen during the whole spring and summer. Notwith- 

 standing this, all these female Aphides without any communication 

 witli a male are able to propagate their species, and seem to have re- 

 ceived the genial influence not merely for themselves alone but for 

 their posterity to the ninth generation. During the whole summer they 

 are viviparous; and if a young Aphis be taken immediately upon ex- 

 clusion from the mother, and kept apart, it will produce yoimg; which 

 young, if also kept apart, will likewise {)roduce, and so on, without the 

 presence of a male. Towards autumn, however, this singular fructifi- 

 cation begins to lose its wonderful effects ; the Aphides cease to bring 



