13 
4 to 6 or more each day until, by the commencement of June, each 
gall may contain from 100 to 120 of her progeny in various stages of 
development, which, after casting several skins, acquire wings and 
gradually depart in quest of their appropriate food plant provided 
by nature for their offspring. The adult stem-mother, after having 
east her last skin, measures from 1.2 to 1.4™" in length, and is at first 
of a broadly oval or pyriform shape, being broadest near the end of 
the abdomen and slightly tapering toward the head, increasing grad- 
ually in diameter during the increase of and development of her ova 
until she becomes almost globular. She is of a dark purplish color, 
with the eyes black and the antennz and legs dusky. At first she is 
dusted with a white, powdery secretion, which is soon followed by a 
rather long, white, and shaggy secretion, covering almost the entire 
abdomen. This secretion is, however, gradually more or less com- 
pletely lost as the oc- 
cupants of the gall in- 
crease in numbers, be- 
ing rubbed off by the 
movements of the in- 
habitants as well as by 
coming in contact with 
the wallsof the gall and 
the globules of ejected 
liquids which gradu- 
ally accumulate. The 
antenne and legs are 
very similar to those 
of the third stage, al- Fic. 4.—Hormaphis hamamelidis; a, adult stem-mother, dor- 
though the digitules ap- pene b, ventral view; c, antenna—much enlarged 
pear to be slightly eapi- 
tate. Those of the claws are very fine and about the length of the 
claws. The rostrum is short and stout and reaches only between 
the anterior and median coxe. There is now a distinct, though 
rather short and broad, almost semicircular tail, bearing two fine 
bristles, while the last abdominal segment, which is more or less com- 
pletely covered by the tail, has become distinctly bilobed, each lobe 
being provided with two stout bristles arising from small tubercles, » 
the edge of both sides being also lined with small spines. After being 
completely exhausted and empty of ova the stem-mother shrivels up 
and dies. 
SECOND OR MIGRATORY GHNERATION. 
The development of the second generation, or progeny of the stem- 
mother or gall-maker, is more rapid, and is completed within sixteen 
to twenty days, all of which prove to belong to the migratory form. 
The earliest of these migrants make their appearance toward the end 
