308 THE MICROSCOPE. 



known to gardeners under the name of " the bug," from the injury 



they do to many plants, especially in hothouses. 



Nothing can be more dissimilar in appearance than the two sexes 



of the singular insects Homoptera (fig. 139). The females usually 



form a mere fleshy mass, often nearly destitute of limbs, and remaining 



attached to one spot upon the branches of the plant infested by them, 



from which they continue to suck nutriment, by the agency of their 



rostrum, until they attain a considerable size. 



The males, on the contrary, are generally very 



minute and really elegant creatures, furnished 



with a single pair of filmy wings ; the only 



representatives of the hinder wings being a 



pair of organs somewhat similar to the halteres 



of the Diptera. Hence some etymologists 



have put forward the opinion that the males of 



the Coccina are, in reality, dipterous parasites. 



The abdomen of the male is generally furnished 



with a pair of long filaments. In some in- 

 S.g. ISd. Cochineal Insect. , ii j- i i ■ j.i • i- , , 



1 Male 2. Female. stances the females retam their limbs and 



power of motion through life. 



In one genus of Coccina (Bortkesia), several species of which are 

 found in this country, the female — which, although apterous, is active 

 in all stages — is completely covered with a snow-white secretion, 

 which gives it more the appearance of a little plaster-cast than any 

 thing else. 



In a second tribe, the PhytoplUhiria, or Plant-lice, both sexes are 

 either wingless or furnished with four distinctly veined wings. The 

 rostrum springs apparently from the breast, and the tarsi are two- 

 jointed and furnished with two claws. 



The greater part of this tribe is composed of the Aphides, or Flant- 

 lioe, whose extraordinary history renders them one of the most inter- 

 esting groups of insects. These creatures must be well-known to every 

 one. They are all small animals, with a more or loss flask-shaped body, 

 furnished with six feet and a pair of antennae, and usually with a pair 

 of short tubes close to the extremity of the abdomen, from which a 

 clear sweet secretion exudes. Both sexes are sometimes winged, some- 

 times apterous ; and the individuals of the same species are often 

 winged and apterous at different periods of the year. They all live 

 upon plants, the juices of which they suck ; and when they occur in 

 great numbers, .often cause great damage to vegetation. Gardeners 

 and farmers are well aware of this. Many plants are liable to be 



