ORDER II.—BUGS. 83 
Plant-lice (Aphis). 
Like the preceding insects, the Plant-lice belong to the 
order of Bugs which constitute the Hemipterous Insects. 
They ‘have small round bodies, of a brown, black, yellow, 
or blue color. Some species are provided with wings, some 
others have none; but on the back of all of them may be 
seen two honey-tubes, or honey-warts, from which issues a 
sweet substance very much liked by the Ants. For this 
reason we find even such carnivorous insects as the Ants on 
friendly and intimate terms with the Plant-lice. In fact, 
they are called the milk-cows of the Ants, because the lat- 
ter suck from them the sweet juice of their honey-tubes. 
They are as careful of them as we of our cows, protect 
them from their enemies, and, in case of danger, even carry 
them away in their mouth very carefully to a safe place. 
This sweet fluid of the Plant-lice is also often seen upon 
the branches of trees or shrubs—a glutinous substance 
known by the name of honey-dew, and eagerly sought by 
Ants. If, therefore, we see Ants running up and down the 
branches of trees and shrubs, we may consider it a certain 
indication of the presence of Plant-lice. 
There is scarcely a tree, or bush, or herb that grows in 
our gardens or fields that is not infested with some species 
of Plant-lice; and in spite of their diminutive size, and 
the disgust we naturally have for them, a host of interest- 
ing associations are connected with them. ‘Their manner 
of living, and of reproduction also, have attracted much 
interest. They both deposit their eggs and bring forth 
their young alive—a phenomenon which does not take place 
in any of the four-winged insects. Their multiplication is 
immense, and, considering the size of the animal, really as- 
tonishing ; for it is a well-known fact that one single Plant- 
louse is capable of producing ninety young ones, from which 
spring myriads more. From the month of April to No- 
