27 
and call the species which exhibits the colour-dimorphism ferni;iata, 
Linn, (red), with aberration unidentaria, Haw. (black); and the other 
species xjiadiccaria, Bkh., of ^Yhich ferriKjaria, Haw., is a synonym. Fer- 
riiiiata — iniidrutaria is the subject of my notes this evening. 
From the time when my interest in this insect was first awakened 
(1890), I have reared from the ova no less than 52 separate broods, 
or parts thereof, reckoning three which are still in pupa. Spadicearia 
has received much less attention, as there is no special problem to 
work out there ; but I have bred it about a dozen times. I only once 
tried to cross the two species, and then failed; the entire difference 
in the genital organs seems to indicate that a successful pairing would 
be impossible, or nearly so. Increased experience, gained from the 
study of the large number of imagines bred, leads me to wonder more 
and more that so many entomologists have found the two species 
difficult to separate, and have declared that transition-forms are to be 
found. 
It will be seen, then, that the object of my repeated breeding of 
Coreiiria/(’rriiiiata, Linn., has not been to obtain anything novel in the 
way of hybrids ; nor to work out the question as to its specific validity, 
which was already established ; but solely to obtain the needful 
material for the investigation of the problem already alluded to, of the 
apparent constancy of the black ah. iinidcniaria, Haw. Before pro¬ 
ceeding to detail the results of any of the experiments, it will be well to 
make one or two general observations on this colour question. 
Perhaps the only definite statement of fact which I can venture 
upoii, is that actual intermediate specimens are extremely rare ; this 
is by no means an unusual phenomenon in cases of dimorphic, or rather 
dichromatic, species. Several instances will doubtless occur to you. 
Amongst 897 specimens bred in 33 broods, I find only 13 which I am 
really able to call intermediates between the red and the black forms, 
that is to say, less than l|-%. Of course many others are partially 
intermediate, i.i'., are more or less dull and dark red, but still I have 
no difficulty in classing them amongst the red. The fact that my 
experiments have been directed towards certain objects, and that I 
have therefore comparatively seldom bred from the purely black strains, 
renders my statistics valueless as regards the question which is the 
dominant colour-form in a state of nature. As a matter of fact, the 897 
specimens which I have been studying for my paper this evening show 
the following results: 478 males, of which 201 are red, 270 black, and 
7 intermediate ; 419 females, of which 195 are red, 218 black, and G 
intermediate, the total being 396 red specimens, 488 black, and 13 
intermediate, bh'om observations iir the field, and from some theoris¬ 
ing upoir which I have ventured as a result of my experiments, I incline 
to think that in a state of nature we should get a much higher per¬ 
centage of black specimens than this, though there are probably some 
localities in which the red are more prevalent; Mr. ^Y. B. Thornhill, 
of Castle Bellingham, Ireland, seems to get more red examples than 
black. 
When we come to mere matters of speculation, we find a wider field. 
Perhaps the principal questions which present themselves to the 
enquirer are : 1st, Which is the original colour in this species ? and 
2nd, What purpose does the dimorphism subserve, or how was it 
brought about? Unfortunately neither of these are questions upon 
