158 
THE ENTOMOLOGIST’S WEEKLY INTELLIGENCER. 
f risen but for the almost microscopic di- 
mensions of the creatures ; and at the 
same time I would premise that I am 
decidedly opposed to the creation of spe- 
cies on imaginary differences, and that it 
is pos.sible that some few, now considered 
distinct, uiay, when their habits become 
more known, sink to the rank of varieties ; 
but that food has any more than the very 
slightest influence in causing such varia- 
tion is, I think, very doubtful. Cole- 
ophora olivaceella is an insect which, in 
the perfect state, is very similar to C. soli- 
tariella, and, moreover, the two larvae feed 
for at least the greater portion of their 
existence as such simultaneously on the 
same plant (Slellaria Holostea) ; but the 
cases of the larvae and their mode of 
feeding are so very different that all who 
believe in species at all must consider 
them distinct. These differences are not 
worth pointing out here ; they have 
already been elaborately detailed by Mr. 
Stainton in the ‘ Entomologist’s Annual’ 
and ‘ Intelligencer,’ and by M. Fologne 
in the ‘ Transactions de la Societe Ento- 
mologique Beige.’ Take again Nepticula 
ulmivora, which is extremely similar to 
N. marginecolella and both larvae mine at 
the same time in elm leaves, sometimes 
sharing the same leaf, yet the larvae differ 
in colour, and mine in a distinct method, 
and each larva invariably produces an 
imago having small, though constant, 
distinctive characters, so that no one can 
believe them identical. 
Similar instances, might be multiplied 
among the Micro-Lepidoptera almost ad 
infinitum. Yet it is constantly hinted 
that two insects, which — iu addition to 
having equal peculiarities with those 
before mentioned — feed in a different 
plant, may be only varieties of one caused 
by the latter circumstance. Now, on the 
contrary, does it not seem mure natural 
to suppose that, if there were doubt about 
the matter, this should rather turn the 
scales, and cause us at once to consider 
them distinct? In many genera in which 
the individual species vary the least the 
larva of each species affects many different 
plants, the specimens bred differing only 
slightly in size and depth of colour. And, 
again, as far as my small experience goes, 
the species of other genera have each 
their own food-plaut, or perhaps frequent 
one or two closely allied species. That 
differences so great as even to be called 
varieties can be produced by change of 
food I must believe to be impossible. All 
who have paid any attention to breeding 
Lepidoptera will readily say how im- 
possible it is to produce varieties at will, 
and how an occasional specimen will 
make its appearance with such peculiari- 
ties of form and markings that, had it 
been taken at large, with no knowledge 
of its previous history, it would have stood 
a fair chance of remaining undetermined 
or described as new, but which has been 
bred from the same brood of eggs kept 
under preeisely the same circumstances. 
And certain species of Peronea are fami- 
liar instances of the imago varying to 
such an extent that scarcely two can be 
found precisely alike, while the larva; feed 
on the same plant and present no diffe- 
rences. On the other hand, in certain 
genera, — for instance, Eupithecia, — in 
many species the larvte, though reared 
from the same brood of eggs and fed 
together on the same plant, will vary as 
much as the imago of Peronea, yet the 
perfect insects produced from these are 
identical in appearance. From these and 
a thousand other instances that might be 
cited, it does appear to me that variation 
caused by the food of the larva does not 
exist, except as to size and tone of colora- 
tion, and that any diflerences iu the 
