HO 
THE APHIS YASTATOR. 
THE APHIS VASTATOR, 
This species of the family of insects, com- 
monly known by the name of " Green-fly," is 
determined by Mr. Smee, in his recent work 
on' the Potato Plant,* as the cause of the 
malady which has affected the crops of that 
vegetable ; and his opinion has not been hastily 
formed, but has evidently been the result of 
careful, extensive, and original investigation. 
We cannot, indeed, fully coincide in Mr. Smee's 
views ; although in the absence of any positive 
and certain explanation of this really import- 
ant question, the insect theory, supported as it 
is by such an amount of circumstantial evi- 
dence as this gentleman has recorded, may 
fairly lay claim to as much consideration as any 
other that has been broached. 
TVe glean the following particulars of the 
aphis from Mr. Smee's book : — 
* "The Potato Plant: its Uses and Properties: 
together with the Cause of the Present Malady. The 
Extension of that Disease to other Plants, the Question 
of Famine arising therefrom, and the Best Means of 
Averting that Calamity." By Alfred Smee, F.R.S., 
Surgeon to the Bank of England, to the Eoyal General 
Dispensary, to the Central London Ophthalmic Institu- 
tion, and Lecturer on Surgery at the Aldersgate School 
of Medicine. Illustrated with ten Lithographs. Lon- 
don : Longman, Brown, Green, and Longmans, Pater- 
noster-row. 
The Aphis vastator, when full grown, is 
about the tenth of an inch long. In very early life 
its body is nearly transparent ; later, it is of an 
olive colour ; at other times it is grass green ; 
and at a later period may be found of a reddish 
colour. It is found in three stages of exist- 
ence — the larva, the pupa, and the imago, or 
perfect-winged insect, in all of which states it 
feeds, remains active, and probably multiplies. 
The antennae, or horns, are seven -jointed, 
nearly as long as the body, and sometimes 
even longer. When the creature is at rest, 
and feeding quietly, these lie reflexed over his 
back ; but when he is roving about they are 
extended before him. The rostrum, or pro- 
boscis, is about one-fourth as long as the body, 
and contains a fine apparatus for piercing 
plants : this instrument, when open, presents 
three diverging delicate piercers, or lancets, 
one of which answers to the tongue, and the 
others to the jaws of insects. The head 
has fine spines upon it. The eyes are red or 
black, and so strongly coloured that they may 
be seen through the membrane which en- 
velopes the insect before it is born. The ab- 
domen is very angular, and is furnished 
towards the extremity with two tubercles, 
which extend posteriorly as far as the apex 
