520 The American Naturalist. [June, 
tember, 1892, makes a significant remark to the same effect: 
“The larva of Pronuba uses up only from 10 to 12 seeds, s0 
that even in those capsules where the most abundant larvæ 
develop, hundreds of good seeds are nevertheless developed. 
The few seeds destroyed may well be sacrificed to insure the 
pollination and development of the others.” 
Ethieally, there is nothing in the phenomena of symbiosis 
to justify the sentimentalism they have excited in certain 
writers. Practically, in some instances, symbiosis seems to 
result in mutual advantage. Inall cases it results advantage- 
ously to one of the parties, and we can never be sure that the 
other would not have been nearly as well off, if left to itself. 
