18 BRITISH OAK GALLS. 
the oak-apple. It is on record (‘ Alternating Genera- 
tions, pp. 77-79) that Mr. Francis Walker reared 
from a number of these galls specimens of Insects, 
Arachnidx, and Acari, belonging to seventy-five species. 
The effect upon this gall is to increase its rotundity 
rather than to produce malformation in its contour. 
A normal mature specimen measures about 8 cm. in 
girth, whereas one containing a host of Inquilmes and 
parasites measured 18 cm. in girth—an exceedingly 
fine specimen. 
SMELL. 
Collectors of galls are aware that many species 
possess a distinctive odour, which it would appear acts 
asa means of defence against enemies other than 
inquilines and parasites. 
Cameron has ably summed up the subject in the 
following manner: “This phenomenon is doubtless 
accompanied by some noxious principles which make 
the larve unpalatable to birds, etc., and is found 
chiefly in the larger species which inhabit large galls 
all the year round. Both the larva and imago may 
give out an offensive odour. C. Kollari and Dryophanta 
folii (= scutellaris of this work) are cases in point. 
The smell given out is usually bug-like, but 
Paszlavsky (‘ Wien. Ent. Zeit.,’ 1883, 1380) mentions 
that D. folit has the smell of ripe apples, A. radicis 
of lemon, A. Sieboldi and CO. tinctoria of caramel or 
fresh malt, with a trace of bug-smell. According to 
the same authority the foli individuals bred from 
the Sessile-Oak have the smell much more intense 
than those from the pedunculated species” (‘ Brit. 
Phyto. Hymen.,’ vol. iv, p. 15). 
TASTE. 
The taste of oak galls to the human palate does not 
appear to have been described in any writings. That, 
