( lxiv ) 
the patience and ingenuity he has displayed in his investiga- 
tions, and the brilliant style in which he has described the 
latter, can be only understood by his readers. Undoubtedly 
his recent volume is a most valuable addition to entomo- 
logical literature. M. Fabre considers that his observations 
on instinct shew it to be quite irreconcilable with the modern 
theory of organic evolution, and constantly expresses this 
opinion in the most frank manner. Still I am of opinion 
that he has completely failed to establish this view. 
Undoubtedly there is very much that we cannot yet under- 
stand in insect instinct. This is due, I believe, in part, to 
our complete ignorance of the nature of their senses, and in 
part also to the fact that we do not sufficiently realise the 
profound differences that exist between the most fundamental 
of the vital functions of insects and those of the Vertebrata, 
including ourselves. The most important of the peculiarities 
of instinct are, perhaps, its limited range of adaptability, 
that is the small amount of variability according to circum- 
stances, and its perfection within its own limits. Lubbock 
has already, if I recollect right, suggested that these charac- 
teristics are probably a consequence or correlative of the 
short life of the individual insect, and I think it is possible to 
get a glimpse, although a very imperfect one, of the ways in 
which they may have been evoluted. If it is shown that the 
abbreviation of the individual life of the insect may have 
been conducive to the preservation of the race, and that the 
peculiarities of their instinct may be consequential to, or 
correlative with the short life-cycle, I think that is all that 
evolutionists need require at present. 
That the abbreviation of the life-cycle may be an advan- 
tage is shown by the case of the flesh-feeding Muscide ; the 
competition in nature for flesh-food is so severe, ranging from 
micro-organisms to carnivorous mammalia, that itis perfectly 
certain that a larva of a Sarcophaga that can eat enough in 
two days to serve the purposes of its metamorphosis, must 
have a great advantage over those that are slower: this is so 
evident, that it is unnecessary to dwell on it. But it may be 
said that this is an exceptional case; and it certainly is so ; 
but there are other considerations which show us that 
