566 The Potato Disease. 
THE POTATO DISEASE. 
BY N. GOODSELL. 
I have read an article in the November No. of your "American 
Journal of Agriculture and Science," written by Prof. Dewey, on 
the potato disease. From the length with which he dwells upon 
causes of the disease, as advanced by a Mr. Smee, an English 
surgeon, might lead some of your readers to suppose that Prof. 
Dewey had confidence in the positions assumed by Mr. Smee. 
Such, however, I presume is not the ease, for near the close of his 
remarks he says, " After all the examination and reasoning of Mr. 
Smee, there seems to be only a remote probability that he has as- 
certained the cause of the potato disease." On the contrary the 
insect which he names as doing the injury, is incapable of doing 
it in the way he describes. He says, " The solid portion of the 
sap is extracted by the insect, and the remaining sap being too 
fluid, does not perform its proper office, &c." This insect Mr. 
Smee names Jlphis vastator, but says it is the JipJiis rapae of 
Curtis. If this is correct, then it is certain that he does not feed 
upon any solid part of the plant, as his anatomical structure would 
prevent his so doing. This numerous family of insects are a 
genera of the Third Order in the Fourth Class in Entomology. 
This class is called Ptilota, and includes winged insects, and the 
Third Order, Hemiptera, includes those which have one half of 
their wings thicker than the other, the front half being opake 
while the hinder part is thin and filmy. In many species of this 
genus the males only have wings, and are seldom seen during 
midsummer, as their presence does not appear to be necessary for 
the purpose of propagating their species, and the females con- 
tinue to bring forth females only, for several months, without the 
intervention of the males. During this part of the season they 
are viviparous, which professor D. seems to doubt. As autumn 
approaches, and the weather becomes cool, winged males may be 
seen among the females, which then become oviparous, and pro- 
duce eggs which are deposited upon plants where they remain 
until hatched by the warmth of the following spring. This ap- 
pears a very singular arrangement in the order of nature that the 
same insect should be both oviparous, and viviparous. Yet such 
is the fact, and was it not for this, we might expect that they 
would soon become extinct, as their tender bodies do not appear 
capable of withstanding the frosts of our northern winters. 
For the above reasons I would recommend our American farm- 
ters, to continue their observations, and search for the cause of this 
disease without placing the least confidence in the theory of Mr 
Smee. 
RocJrester, JVovember 24:th, 1848. 
