BEITISH APHIDES. 
INTRODUOTION. 
Throughout tlie entire class of Insects, probably no 
single family has had more attention bestowed upon 
it than the family of Aphides or Plant-lice. The last 
century produced many inquirers into their economy ; 
their writings provoked much discussion, and their 
discoveries in this special field of Entomology raised 
important questions, which even now acute anatomists 
and students of morphology have not wholly been able 
to sbt at rest. 
The superficial observer often has a tendency to 
connect the importance of a subject with characters 
that most directly appeal to our senses, such as mere 
extension or size, forgetting that perhaps our ideas are 
lost as completely in the contemplation of the infinitely , 
little as in the attempt to realize the thought of the 
infinitely great. The energies and phenomena con- 
tained within the ultimate cell no one yet knows, and 
possibly here cannot know. 
Bacon says, Man, the servant and interpreter of 
nature, can only understand and act in proportion as he 
observes or contemplates the order of nature ; more he 
can neither know nor do.”^ Again, the same philosopher 
* Bacon’s words are-— “ Katnrse minister et interpres tantnm facit et 
intelligit quantum de naturse ordine se vel mente observaverit. Nec 
amplius scit aut potest,” &c . — Novum organon scientiarum. 
1 
