(2 3 [Ivii 
for some time past to verify the statements that have been 
made on this head, and also to ascertain whether other species 
of our common butterflies likewise possess a characteristic 
odour, 
“Tn the summer of 1899 I made the following observations :— 
A fresh specimen of G. napi, ¢, when seized with forceps, gave 
out a strong perfume very like the crushed leaf of a ‘lemon 
plant.’ The wings removed from the body retained the odour, 
which was also perceptible on the fingers when they had been 
used for rubbing the scales off the wing. A brush similarly 
used for removing the scales emitted the odour strongly. The 
body, though crushed, was odourless. A trial made with G. 
brassicx, 3, gave a negative result, but on subjecting a speci- 
men of G. rapx, dg, to similar treatment, I fancied, but could 
not be absolutely certain, that a faint sweetish odour was 
perceptible. 
“Tn the early autumn of 1900 I failed to detect any odour 
in a specimen of Colias edusa, ¢, which had been dead about 
twenty-four hours, but a few days later I repeated the trial 
with the following result :—A living C. edusa, ¢, was allowed 
to flutter about the room for a few minutes, then taken in the 
fingers and held gently. No odour was apparent, even when 
the so-called ‘ glands’ on the costa of the hind-wing (which are 
well known to be absent in C’. hyale) were uncovered. The 
‘glandular’ patch of the right hind-wing was then carefully 
scraped with a penknife, and the little mass of .scales thus 
detached was immediately smelt. There was a distinct 
sweetish and almost spicy odour which I should compare to 
heliotrope. It soon passed off, or I ceased to appreciate it. 
The patch on the left hind-wing was similarly scraped, with 
the same result, except that the odour seemed fainter. A trial 
was made with another specimen that had been dead at least 
twenty-four hours. As in the first case, I could not be sure 
that I detected the heliotrope odour. On crushing the thorax 
there appeared to be a slight scent somewhat like that of fresh 
varnish, and this seemed also to attach to the ‘scent-scales’ 
when scraped off the glandular patch. But it bore no resem- 
blance to the perfume found in the living specimen. <A few 
days later I convinced myself that the scales of the upper 
surface of the wings in G. rapx, ¢, about which I had at first 
