252 Memoirs of the Indian Museum. [Vor. VI, 
The eggs are oval, about twice as long as broad and sticky on one side, on account 
of the glue with which they are fastened down. They are yellow when first . but 
soon turn shining black. Length 0:5 or & a millimetre. 
The oviparous females can be observed in early January coursing up and down 
the branches, and often they wander a good deal with an egg sticking out through 
the genital aperture, before depositing it in any convenient place. 
The young twigs of the Indian Elm are very tomentose and frequently the eggs 
are buried in the hairs ; they may also be glued on to any roughened surface ; small 
lenticels which appear about this time are sometimes chosen for the purpose. But 
the most favourite places are either small cracks in the bark or the ventral surfaces 
of any scales which cover the future shoots and happen to be sticking out. These 
eggs are quite bare and, so far as I have observed, no waxy flocculence is used to 
hide them from view, as noticed in the case of Phyllaphis (Weed, Nat. Hist. of Ameri- 
can Insects). 
Natural history and life-cycle.—After one or two winter rains, about the middle or 
the latter part of December, followed by cold winds and frosty nights in Lahore, the 
leaves of Celtis trees begin to turn yellow and slowly drop off. For the most part of 
January and February the larger trees are all bare and without foliage. At this time 
there are hardly any living Aphids present ; only the eggs that are deposited by the 
oviparous females in January are to be met with after a carefulsearch. In early March 
or even in the last week of February the plants begin to put forth their tender leaves 
and the Aphid eggs also hatch at this time. The young from these eggs are what are 
termed stem-mothers. They start the colonies and about the roth or 12th of March 
one may notice these flocculent apterous females with a brood of four or five young, 
produced parthenogenetically. They resemble in all essential features the apterous 
viviparous females of later generations. After two or three generations, as the young 
develop into viviparous females*and begin to reproduce actively, the winged females 
are produced. These are the alate migrants that fly off to other plants or to different 
parts of the same plant. They also give birth viviparously to apterous females, with- 
out the usual fertilisation. So that even in March we find plenty of alate and a 
females which multiply rapidly. 
Habits.— These insects are extremely sensitive and with the slightest touch or 
shake of the leaf on which they are resting, they jump off and either fall to the ground 
or to a lower leaf or fly off. Only the very young specimens and those in the act of 
reproducing are disinclined to move. 
Pink forms.—Most of the individuals at this time are of a greenish colour, with a 
brown or blackish tinge, though in April and May some pink-coloured forms are also 
to be met with. The size is very variable; one may find individuals hardly exceed- 
ing one millimetre in length, while others may be a little less than two. 
Honey-dew is passed very copiously. 
There is a marked decrease in their numbers in the second half of May and 
hardly any are to be seen on the lower branches of the trees in June. For the last 
three years I have not had the opportunity of staying in Lahore from June to Sep- 
