PREFACE . 
When the subject of the British Aphides was 
pressed on the attention of the Author by an old 
friend and competent Entomologist, it was believed 
that what had to be said could be comprised in a small 
compass ; but materials have accumulated, and the 
anticipated single volume has considerably swelled its 
dimensions. JSTot withstanding this expansion, the 
Author has a lively sense of his omissions and short- 
comings. 
Like that of the Bee and the Ant, the history and 
the economy of Aphis is elaborate. Individual species 
for several months demand attention, if their develop- 
ment and life-history is to be at all adequately 
considered, and to do this well, a single group, like 
that of the underground Aphides, should be taken in 
hand at one time. 
Though this present work cannot pretend to take 
an exhaustive view of this special department of 
Entomology, it has been thought better to make 
immediate use of such material as has been collected, 
rather than defer to an indefinite time a more com- 
plete history. 
By a constant use of the camera lucida, and by 
employing living insects only for figuring, it is 
believed that trustworthy outlines have been obtained. 
Whilst, however, the camera lucida has. the advantage 
of showing the insect in a life-like attitude, it has also 
the drawback of rendering the figure measurements 
