50 
THE entomologist’s RECORD. 
varieties in this way would generally be variations in size, as in 
the case of the before-mentioned species, Hypsipetes ehitata, 
and not variations in colour. 
My friend. Dr. Chapman, I know, always connects the 
beautiful var. rosea of Cuspidia tridens with cherry {^Ent. Rec. 
ii., p. 31), but I do not know that he has formed any idea as 
to the way in which the colour may be produced by this food, and 
I simply mention the fact to show that other lepidopterists 
consider that food does influence colour. Exact experiment 
on the matter is undoubtedly needed. 
There is one way, however, in which food may more or less 
indirectly produce a dark coloration. A plentiful supply of succu- 
lent and nutritious food will generally produce insects of large 
size, whilst an insufficient supply of food, or even a plentiful 
supply of innutritious food will act in the opposite direction. 
In these specimens, however, the smaller size is often accom- 
panied by the markings being pressed much more closely 
together,’ thus giving the insect a darker appearance. This is 
especially the case if the ground colour be pale and the markings 
dark, for then the area of the pale ground colour becomes 
lessened, and the darker markings are developed in a smaller 
space. It becomes hard to dissociate this form of develop- 
ment from an indirect tendency to disease, or rather to a 
change of constitution as Dr. Chapman terms it ; but all 
instances of this kind appear to be only very indirectly caused 
by food,, and will be found, generally, to be governed by the 
environment of the particular species. 
In the Ent. Mo, Mag., vol. xiii., p. 132, we find Mr. Birchall 
attempting to show us that “ there are great constitutional 
differences in animals and plants, which are correlated with 
differences of colour,” and he refers to chaps, xxi. and xxv. of 
Darwin’s Ani?/ials and Plants under Domestication, where he 
states it is shown “ that black and dark-coloured animals 
escape man}^ diseases, are less liable to the attacks of parasites, 
and will stand changes of temperature, which prove fatal to the 
lighter coloured varieties.” Unless in the case of true 
albinisms, I should challenge this statement. We must bear 
in mind that true ‘‘ albinisms,” which must not be confounded 
with ‘Meucochroisms,” are generally looked upon by scientific 
men as being a certain form of disease, or rather due to certain 
conditions of disease, and we can readily understand that, if 
this be so, the white varieties would necessarily be constitu- 
tionally weaker than their darker brethren. Mr. Birchall then 
