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tributed. Actual observation shows that these insects, small as 
they are, are decidedly heavier than the atmosphere, and that 
their tendency is to fall to the ground, at no great distance from 
the tree. That they are carried by the wind to great distances, 
under any ordinary circumstances, is extremely improbable. To 
produce this result we must assume the coincidence of a violent 
gale or hurricane, such as would very rarely occur at any one time 
year after year. And I repeat, lest it should be lost sight of by those 
who are not familiar with the history of this insect, that there are 
but three or four days in the year in which it is not immovably 
fixed to the tree. In view of the inadequacy of all the theories 
thus far propounded, it must be admitted that the rapid and wide¬ 
spread dissemination of the Apple-tree Bark-louse is yet involved 
in much mystery, and that such instances as the occurrence of the 
Bark-louse on the isolated crab tree above mentioned, remain to be 
explained. 
The instrument by which this insect draws its nutriment from 
the tree, is in the form of a long and extremely slender proboscis 
or sucker, with a glossy surface and a redish tint, exactly resem¬ 
bling a very fine hair. It is so delicate and fragile that it is usually 
broken off in the act of removing the scale from the bark, and as 
it generally parts at its juncture with the insect’s body, it escaped 
for a long time the notice of the most careful observers. Even so 
acute an entomologist as Mr. Walsh, so late as the time of the 
publication of his Report in December, 1867, although he pre¬ 
sumed from analogy that such an organ must exist, and though it 
had been discovered and described by European authors in the case 
of allied species of the same family, nevertheless admits that “ as 
to any organized beak he could discover nothing of the kind.” And 
Mr. Riley, in his first Report, published a year later, says: 
“ Though from analogy it must have a beak of some kind, it is so 
exceedingly fine and fragile, that I have never been able to per¬ 
ceive it.” I had myself also examined hundreds of bark-lice 
without detecting the proboscis, and indeed did not see it till 
after I had discovered it in another and closely allied species, the 
Coccus of the pine leaf. I had noticed that in raising these scales, 
they did not always drop from the leaf, but sometimes hung flut¬ 
tering from its surface, as if suspended by an invisible thread. This 
occurred so many times that my curiosity became excited to know 
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