oY 
and four of Athyma punctata, both beautiful mimics on both 
upper- and under-sides of the male of Hypolimuas misippus, 
a model which is abundant far away to the South in the 
tropics, but becomes much rarer in N. India, and in all the 
25 years of Monsieur Oberthiir’s experience has never been 
known in W. China, where the mimics are found. We are 
driven to suggest two alternative hypotheses: (1) that the 
model, which is known to be a wide-ranging insect with 
immense powers of flight, has visited W. China sufficiently 
often and for sufficiently long periods to render the mimetic 
resemblance advantageous. Against this it may be urged that 
H1. misippus is a tropical butterfly, and that it is improbable 
that it would reach or, at any rate, establish itself in such 
a latitude at such an elevation as e.g. Ta-tsien-lu ; (2) a more 
probable hypothesis is afforded by the lines of migratory 
birds, applying in the temperate zone, where they nest, the 
experience learnt in the tropics. If a bird’s experience of the 
male of H/. mzsippus be an unpleasant one, it follows that 
a modification in the pattern of any butterfly which suggests 
the same experience and leads to a cautious attack or perhaps 
averts attack altogether, will be advantageous. A\ll that is 
necessary is that the same enemy should see the two insects. 
If this be achieved it matters not how many hundreds of 
miles may intervene between model and mimic. The two 
northern mimics belong to genera which have in their colours 
and patterns considerable resemblance to those of the 
model ; so that it is possible to understand why this species 
instead of any other distasteful resident in the tropics, has 
been imitated. The hypothesis suggests inquiry into the 
species of migratory birds, the routes followed, and dates of 
arrival and departure. 
It will be realized that these 25 specimens bear in the most 
interesting manner upon the very questions which, more than 
all others, are studied in the Hope Department. 
Twenty-five insects of various Orders from St. Moritz and 
Ragatz (July 1903) were presented by the captor, Hamilton 
H. Druce, Esq: 
