144 
THE SCENTS OF BUTTERFLIES 
The chemical composition of the water therefore gives no 
clue to the colouring matter, which is probably of organic 
origin and produced by an organism capable of growing in a 
practically saturated alkaline brine. 
We should be glad to know of the occurrence of similar red 
brines and the causes of the colouration. 
Edinburgh University, March 21, 1912. 
THE SCENTS OF BUTTERFLIES 
By Rev. St. Aubyn Rogers, M.A. 
I suppose that most naturalists who have had much ex- 
perience in collecting butterflies in the tropics are aware that 
many insects of this order have scents, and it is probable that 
in the majority of cases experience has shown that the scents 
are disagreeable. 
This subject has engaged the attention of many observers 
in recent years, and it appears that there is no doubt that the 
scents of butterflies are of two distinct kinds, the unpleasant 
scents being common to both sexes, but there is also in many 
species a decidedly pleasant odour, which is usually confined 
to the males. Many of these latter have abundant scent- 
scales which are not found in the female, and are in some 
cases aggregated together so as to form what are known as 
sex marks. 
The unpleasant odours are especially characteristic of 
protected butterflies, such as the Danaince, Acrceince, and, in 
the New World, the Heliconince. Some of the common Acrceince 
in East Africa have a very decided unpleasant odour, e.g. 
A. anemosa, and Planema montana. The same is true of 
many Danaince, and it is remarkable that, on the other hand, 
several of the Ithomiince, which represent the Danaince in the 
New World, have pleasant scents. One of the strongest 
scents of which I have personal experience is that of the 
Ithomiine Tithorea Megara, which appears to me to resemble 
closely the scent of the common double pink. 
These pleasant scents are, however, most characteristic of 
