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tions have extended, it is rarely found upon them, and even prefers 
the sweeter kinds among the cultivated varieties, at least such appears 
to be the opinion of Dr. Fitch. Blot says it is confined to the apple, 
and if placed on any other tree will soon perish. He also adds fur¬ 
ther, that while it does not attack the flowers, fruit or leaves, but fixes 
itself upon the bark, it will penetrate to the roots . That the root and 
trunk forms are of the same species, appears to have been long known 
in Europe. 
Its mode of spreading or migrating, and of hibernating have been 
given again and again by different writers, apparently without any 
doubt whatever as to the correctness of the statement. The most re¬ 
cent publication of this theory which I have seen, where it is likely 
to be read by agriculturists and horticulturists, is an article in a late 
number of the Rural New-Yorker , by Mr. B. Pickman Mann, of 
Cambridge, Mass. The writer gives the history and habits of the 
species correctly, as found in the books, omitting the discussion of dis¬ 
puted points, as importation, &c. Following out the idea advanced 
by Prof. Verrill, in an article published in the Practical Entomologist, 
(vol. 1, 18G5), he states that the winged females appearing late in the 
fall, fly from tree to tree, deposit their eggs, which remain over the 
winter, and are hatched the following spring. Thus the mode of 
spreading, and the method of passing the winter are given in a single 
sentence; at least what is-supposed to be the general rule. But it is 
proper to add that Prof. Verrill speaks of finding living specimens in 
December, and concludes that many of these insects pass the winter 
in the cracks and crevices of the bark, covered by their cottony se¬ 
cretions. 
I allude to these statements not for the purpose of criticising them, 
but in order to present some reasons for doubting their correctness as 
to one or tw r o points which are important, when w r e come to consider 
the best means of destroying them. I allude especially to the sup¬ 
position that the oviparous female flies from tree to tree to deposit 
her eggs for the spring brood. As neither Prof. Verrill or Mr. Mann 
refer to personal observations on this point, I presume it is a theory 
based upon the known habit of some other species, as the Aphis mall, 
of depositing eggs in the fall to hibernate. 
It is now pretty well ascertained, as stated in the introduction to 
this paper, that the oviparous female of the true Aphides ( Aphidince ) 
is always wingless, and that the wfinged female is viviparous. It is 
true that in the Chermesince , some of the species develope winged ovi¬ 
parous females, and I think it more than probable that the same thing 
occurs among the gall making species of the sub-family now 7 under 
consideration, but there are strong reasons to doubt it in reference to 
the species of Schizoneura , whose habits are similar to those of the 
wooly aphis of the apple-tree. Koch states that the “Altmutter” 
(colony foundress) of tw r o of the species of this genus are apterous; 
the Almtutter of one species he describes as winged, but it appears 
in the spring and is evidently viviparous. Analogy and the facts 
w r ould therefore lead us to the conclusion that the winged female 
viviparous. 
But there are additional reasons for doubting the correctness of the 
opinion advanced by Prof. Verrill on this point. One is the fact he 
states showing their pow y er of enduring cold, which is confirmed by 
