I—COLLECTING AND OBSERVING. 
in the breeding cage, before the larve are quite full grown. 
Larve which hybernate during the winter are the most diffi- 
eult of all to successfully rear in captivity, and in such 
cases the observer must use his ingenuity in reproducing, 
as far as possible, the conditions under which the larvze 
spend the winter months when in their natural surround- 
ings. Except in the case of species whose life histories are 
already well known, different kinds of larve should always 
be kept in separate cages, and a small card enclosed in each 
cage giving the date and a reference to the page in the 
diary where the description and account of the habits of 
the larvae appear. Unless this be systematically done, there 
will often be serious difficulty in correctly assigning a larval 
description, or drawing, to the perfect insect which has 
actually resulted from the larva. In many eases Lepidop- 
tera remain in the pupa state for some months during the 
winter and, unless special precautions are taken, the ob- 
server will be very liable to forget about the larve he had 
under observation the previous autumn. From personal 
experience extending over many years, I can strongly re- 
commend the system here described as being much more 
convenient and accurate than the older system of keeping 
a numbered list of breeding cages with their inmates. By 
using the cards, the observer can constantly change his 
larvae or pupae, from one cage to another, provided he 
always changes the cards with them, and as every breeder 
-~I 
of insects is well aware, such changes frequently have to be 
made in order to provide accommodation for fresh batches 
of larve as they come to hand. The importance of provid- 
ing for the certain identification of larve, with their 
relative perfect insects, has been insisted on at some 
length, as so many cases have occurred where collectors 
have bred species of the greatest interest, but have after- 
wards been unable to furnish any information as to their 
life histories. 
Quite apart from the discoveries of new life histories, 
information of great scientific value can often be obtained 
by an observant breeder of insects, and the following may 
be specified as examples:—The inheritance of remarkable 
individual variations from parent to offspring; the influence 
of different food plants, environments and temperatures 
on the resultant perfect msects; the existence of seasonal 
variations; the precise nature and meaning of the protec- 
tive coloration, structure and instincts of larve; ete., ete. 
When breeding large numbers of individuals of one 
species, an exact record of the number of each sex bred is 
of great value and should always be kept. Until such 
records are more generally available, the precise proportion 
of male and female individuals in different species of insects 
cannot be accurately determined, although there are good 
reasons for considering that, in most species of Lepidoptera 
males are more numerous than females. 

