APHILOTHRIX CORTICIS. 8L 
‘i The larva pupates in the gall. The imago emerges during 
une. 
Parasite, No. 158. Inquiline, No. 131. 
Alternate sexual generation: Andricus gemmatus, Adler. 
This species of gall is often more or less concealed 
by dead leaves, moss, or loose earth, but sometimes 
situated prominently in a callus or other incrassation 
of a stub. 
The autumn—winter condition of these galls is shown 
in Plate XXII, div. A. 
Embedded deeply in the bark, and not easy to see, 
because of their brownish colour, these galls are 
constantly overlooked. It is only during the very 
earliest period of exposure, and later on. after the 
imagines have eaten their way out, that the galls 
attract attention—in the former condition by reason 
of their pale colour, in the latter, because of the 
clusters of little holes. 
They occur in aggregations, and vary in numbers 
from three or four to forty or more, very rarely less 
than three; mostly in a deep split in the bark; 
frequently in a callus resulting from injury, or in the 
new growth where a limb has been removed; some- 
times in semi-exposed roots; and occasionally in the 
axis of a bough growing out from the bole of the tree. 
The shape of this gall is fairly constant, obconical 
being the type. It varies, however, especially during 
the period before maturity, when it may be oval with 
the lower apex somewhat pointed; this ultimately 
penetrates deeply into the tissue around it. When 
conglomerated they are often greatly distorted, 
flattened longitudinally, and irregular in size and 
form. 
The appearance of the gall when pushing through 
the bark, is glossy, succulent, and fleshy, very pale 
yellow, or greenish. The visible portion known as 
the cap is more or less globose, and about 3 mm. in 
diameter. The structure continues to rise until it is 
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