THE NUMERICAL ASPECT OF OAK GALLS. 23 
Neuroterus fumipennis— 
3453 galls on-15 leaves off one bush. 
Fewest galls on one leaf . . 115 
Most ” rr) ” 2 . 489 
Average per leaf . . 230 
Weight of the galls, 2 dr., a sc., 6 er. 
“ Neuroterus lenticularis— 
1944 galls on 12 leaves off one bush. 
Fewest galls on one leaf . a 
Most fo a AG eS . 288 
Average per leaf . . 162° 
Weight of the galls, 4 dr., a sc., 17 gr. 
These leaves were gathered after twenty- -two days 
without rain. The galls were removed from the 
leaves, counted, and weighed at once, all the figures 
being verified in several ways. 
To ascertain if the galls of N. fumipennis would have 
weighed more had the weather been wet, they were 
spread in a shallow dish and exposed to rain for three 
hours. They were then allowed to dry off superfluous 
moisture. Upon weighing again it was found they 
were 12 grains heavier than before. 
So far as the author’s observations have extended, 
the largest number of galls of a few other species on 
single leaves are : 
Dryophanta scutellaris . 9 on one leaf. 
Spathegaster tricolor 12 cay a 
4 baccarum . 8 yg, 
5 17 ~—s«ysxg«~=Ss cattkin stalk. 
Aphilothria quadrilineatus 35s, 6 és 
Cynips Kollari . : On twig. 
Aphilothrix Sieboldi . . 188 
es corticis . . 82 within an area 4°5 cm. 
in diameter. 
Trigonaspis crustalis . 12 within an area 15 cm. 
in diameter. 
On one leaf, 14 x 9 cm., there were growing: 
1 Newroterus ostreus . 2 Dryophanta scutellaris. 
