Vee 
above was captured on Mt. Masarang in N. Celebes by Dr. 
Chas. Hose in 1895. 
[xl 
Wednesday, June 5th, 1907. 
THE SIGNIFICANCE OF SOME SECONDARY SEXUAL CHARACTERS 
IN Burrerriies.— Professor E. B. Pourton, F.R.S8., said that 
he wished to bring before the Fellows a hypothesis which 
had suggested itself as the outcome of reflections upon the 
Heliconine, as dealt with by Mr. W. J. Kaye in a recent 
communication. 
It had often been noticed that mimetic resemblance is apt 
to deceive the species concerned, so that the male of one will 
chase the female of the other. When model and mimic 
[xli 
belong to very different groups, e.g. sub-families, it is im- 
probable that such errors of judgment could lead to any 
important danger. It is very unlikely that a superficial 
resemblance would mislead the individuals of species 
belonging to different sub-families when they approached 
each other at all closely, and the impression made by each 
upon the whole of the sense-organs of the other became 
at all strong. But this would not apply to anything like the 
same extent when there was near relationship between the 
mimetic species—as in so many ILthomiine, Danaine, and 
Heliconine. When close resemblance obtains within the 
limits of such a sub-family as one of these,—and mimetic 
likeness of the kind is often extraordinarily exact,—it is not a 
far-fetched hypothesis to suggest that some special adaptation 
has arisen, enabling the females easily to discriminate between 
their own and the males of other closely similar species, and at 
once to repel those advances which are something of a danger 
and nothing of advantage to either species. Other facts, and 
especially the hard, pouch-like structure secreted by the male 
upon the body of the female in Parnassius and in Acreine, 
also support the conclusion that useless pairing and attempts 
to pair are an injury to the species. Colour and pattern being 
excluded ex hypothesi, some special difference in scent is 
