1900] BRIEFER ARTICLES 275 
I. These galls are produced during the summer months on the 
young branches and sometimes on acorns. When mature they fall 
from the trees and are nearly globular in shape, varying from 20-30" 
indiameter. They are solid throughout and of the consistency of the 
pulp ofa green apple. Externally they are smooth, and in color are 
a mottled green, yellow, and brownish-red. At this stage they are 
made up of three distinct zones: (1) a central zone, made up of nearly 
isodiametric parenchyma cells packed with numerous small somewhat 
spherical or irregular starch grains which are colored blue with iodine; 
(2) the middle zone, composed of radially elongated parenchyma cells, 
possessing thick cellulose walls with prominent simple pores and 
containing a mass of protoplasm lying on the sides of the walls and 
afew starch grains (with the development of the egg of the insect 
there also appear in the cells of the middle zone numerous starch 
grains closely resembling those found in the central zone); (3) an 
‘ternal layer made up of irregular parenchyma cells somewhat collen- 
chymatic in character, with the protoplasm as in the middle zone. 
Il. Decided changes take place soon after the galls fall from the 
ane (1) A larva develops in the central zone and there are signs of 
aavity in the protoplasm of the cells of this zone. A large nucleus 
= nucleolus lies centrally in the protoplasm and in some cases yel- 
Wish globular vesicles are apparent. These latter are fixed in the 
- Specimens by means of copper acetate (7 per cent. solution), 
age treatment they become more yellowish in color an 
i eS ” chloral, glycerin, potassium hydrate, or 
which, «c ) doubt in the nature of tannin vacuoles. (2) In he galls 
ntain a larva, and have been allowed to remain im Cope? 
Vig Solution for several weeks or months, there separate in the par- 
line oes a the middle layer or zone yellowish crystals or ine 
i 8, which are insoluble in water, chloral, glycerin, or alcohol. 
fan. a. and crystalline bodies are lens-shaped, star-shaped, “4 
din, inulin, and chee resemble the different carbohydrates, as se 
nes are ie which separate in certain plant cells when the spe : 
in ay aced 7” alcohol. These crystals, however, do not Hepae 
'€ material, and are to be found only in galls which have 
ag popper acetate solution. Their appearance, ae 
that ¢, eon with copper gallate crystals lead to the conclus : 
*y are identical in composition with the latter salt. (3) in Me 
layer or zone of specimens which are at this stage of maturity, 
