1072 
stalks of the oak, are obviously due to 
the act of oviposition and not to the func- 
tions of the parts producing it. The red 
galls of the sawfly, Nematus gallicola, 
are found on four different species of 
willow. 
Galls vary remarkably in size and shape 
according to the species of their makers. 
The polythalamous gail, found on the 
roots of old oak trees, may attain the 
size of a man’s fist; the gall of another 
Cynipid, which occurs on the male flow- 
ers of oak, is two millimeters or barely a 
line in length. Many galls are brightly 
colored, as for instance, the oak-leaf hairy 
galls of Spathegaster tricolor, which are 
of a crimson hue. 
The variety of forms of galls is very 
great. Some are like urns or cups, others 
are lenticular. Galls are formed by in- 
sects of several orders Among the 
Hymenoptera are the gall wasps (Cynips 
and their allies), which infect the various 
species of oak. They are small insects 
having straight antennae and a com- 
pressed, usually very short abdomen 
with the second or third segments great- 
ly developed and the rest imbricated and 
concealing the partially coiled oviposi- 
tor. The transformations from the lar- 
val state are completed within the gall, 
out of which the perfect insect tunnels 
its way usually in autumn. though some- 
times after hibernation. 
ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 
Among the commoner galls are the oak 
apple or oak sponge, the currant or ber- 
ry gall, “oak-spangles,’ generally reput- 
ed to be fungoid growths until the discov- 
ery of their true nature by Frederick 
Smith, and the succulent “cherry galls.” 
Galls are formed by the hemopterous and 
homopterous insects. 
Literature 
Hedgecock. Field Studies. 
of Plant Industry Bulletin 186. 
Stewart. New York Experiment Sta- 
tion (Geneva) Bulletin 328. 
Smith, Brown and Townsend. Crown 
Gall on Plants. (Cause and Remedy). 
Bureau of Plant Industry Bulletin 2138. 
Smith, Brown and McCulloch. Strue- 
ture and Development of Crown Gall. 
Bureau of Plant Industry Bulletin 255. 
Smith. Crown Gall and Sarcoma. 
Bureau of Plant Industry Circular 85. 
Mississippi Experiment Station Bulle- 
tin 147. 
The following 
Galls: 
California Experiment Station Bulle- 
tin 192. 
Nevada Experiment Station Bulletin 
91. 
Kentucky Experiment Station Bulletin 
142. 
Bureau of Plant Industry Bulletin 217. 
GRANVILLE LOWTIIER 
See Vegetable. 
Bureau 
deal with Nematode 
GARDEN. 
