80 The Potatoe Plague. 
who feed upon and destroy the seed plants; but this is a 
consequence, and not a cause, for maggots and flies are only 
‘to be found on diseased or putrid vegetables; they riot and 
‘banquet on putrefaction; it is their natural food, and there 
they are only to be found. Plant, then, a sound potatoe in 
a, good soil, and, properly treated, it will find its way to the 
surface, and produce a good crop in defiance of maggots 
and flies, 
The seeds of disease, then, must be in the constitution of the 
plant. 
In examining a diseased potatoe, which has blind eyes, and 
will not germinate, it is plain that there is canker on the 
skin, and plague spots all over it. This, if planted, will cer- 
tainly be attacked by the maggots and flies; but the plant is 
in a state of decay or putrefaction—in fact a caput mortuum 
— and it properly belongs to the flies and maggots by right 
of inheritance. The great object to be attained, then, is to 
plant sound seed, and the maggots and flies will not relish 
it. It is generally allowed, and the idea has been long enter- 
tained, that it is quite impossible to raise seed potatoes in low 
situations or in a high temperature, without being affected 
with the curl; but at an altitude of four hundred feet it 
entirely disappears. In this there appears to be a very re- 
markable peculiarity in the nature and constitution of the 
plant ; but in looking to its origin, general history, cultivation 
and general management in this country,-—its success and 
failure, —I have been led to a far different conclusion. In- 
deed, from what I have already stated, it must clearly appear 
to every one, that there can be only one cause for the fail. 
ure of the potatoe plant, to wit, over-cultivation. 
The first practieal experience of failure which I met with 
on my own farm, struck mé most forcibly. In the year 
1837, Thad a small quantity of potatoes for seed, which I had 
received from high grounds. I thought them very fine, and 
