861 
No. 145.] 
This last is most frequently the situation which she prefers. Punc¬ 
turing the part with her beak she causes a profusion of sap to 
flow from the wound. This evaporating and coagulating becomes 
organized vegetable matter, which gradually grows upward into 
a wall around her, and as she continues to puncture it its growth 
continues until it finally closes together over her, and shuts her 
into a cavity having only sufficient room for her to turn freely 
around in it. Yet within this cell in which she is thus closely im¬ 
prisoned, she is to give birth to several hundreds of young. To 
make the cavity sufficiently roomy for them she continues to 
puncture its walls upon every side, thus causing them to expand. 
Her young also, as soon as'they are born, fix themselves to the 
inner surface of the gall, inserting their beaks therein to feed 
upon the vegetable juices, thus adding to the irritation and expe¬ 
diting the growth of their domicil. Thus as they increase in 
number and size the gall increases, so as to furnish the amount 
of room which each requires, without any vacant space between, 
the whole surface being covered with these young lice. 
It is thus that these excrescences are produced. They are of a 
globular form and of different sizes, from that of a pea to an 
ounce ball, and are attached to the side of the stem the whole 
length of their base, often causing a bend or. distortion ot the 
stem, especially when two or three are contiguous and confluent, 
as they frequently are. The walls of the gall are about the tenth 
of an inch in thickness, and of a succulent fleshy texture, white 
upon the inside and green on the outside at first, but soon becom¬ 
ing discolored with black, which spreads until the w’hole is of 
this color. The hollow’ inside has its surface covered with minute 
smooth shining lice of different ages and sizes, so that it resembles 
the geode of a mineral, the surface of which is lined with a mul¬ 
titude of minute crystals, whose sparkling points are everywhere 
glittering in the light. Numerous dusky specks are also observed 
among the lice. These are the cast skins of the lice, all of which 
moult as they increase in size, their original skins becoming too 
small to contain them, and being of too flam a texture to expand 
with the growth of the insect. 
In addition to the dusky cast skins which have been mentioned, 
in many of the galls numerous round black grains occur. These 
