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same time in single curls of more terminal leaves, we may find the 

 second generation of wingless mothers, surrounded by smaller 

 colonies, all of which will become winged." These winged 

 females of the third generation do not appear to be long-lived, but 

 during their life they produce what may be regarded as living 

 young in great number. I say, what may be so regarded, for 

 although deposited as eggs, and having the appearance of eggs, 

 yet they hatch into living young almost immediately after they 

 come from tlie parent insect. The larvae of this fourth generation 

 seem to be more brisk and active in their movements than any that 

 precede them, and may be seen creeping over the twigs. At first 

 they are reddish in color, but like all the broods they grow darker 

 and browner with age. Like the second generation they have no 

 wings, and like them they attack the leaves, increasing the de- 

 formity begun earlier in the season. Nor do they invariably 

 attack the leaves, but appear to thrive on the younger bark, where 

 sometimes they may be found, of course with no sheltering cover 

 such as the gall affords those on the leaves. They are, however, 

 more or less covered by a cottony substance which they secrete, 

 although this in no way takes the place of the gall, since it is far 

 more delicate, and is easily rubbed oft'. Reproduction goes for- 

 ward rapidly, and they extend themselves over the twigs with corre- 

 sponding rapidity. A phenomenon noticed by Rile}', has not come 

 under my notice, but it is extremely interesting. He says : " At 

 this season of the year, when the lice are thus numerous, they may 

 be found during the heat of the day actively crawling over all por- 

 tions of the tree — a veritable migration necessitated by the want of 

 sufficient succulent leaves, but destined to be the death of the 

 individuals participating in it, excessive multiplication here, as 

 in all other cases, obliging the destruction of the excess." From 

 the fourth generation comes a fifth, which does not differ much 

 from it. This fifth generation gives rise to a second winged 

 brood like the third. This stage in the life of the species is 

 reached in July, or sometimes about the last week in June. I 

 have found them the 26th. They collect in crevices of the bark 

 more than on the leaves or twigs, and in these places the seventh 

 and last generation is produced. These for the first time show 

 clearly sexual distinctions, reproduction up to this time having 

 been asexual. They are dark yellow, or orange, and remain upon 

 or in the crevices of the bark. The mouth is less perfectly devel- 



