SCIENTIFIC NOTES. 139 
and turn round. They can be found in various positions long after 
dark.” : 
«They are equally conspicuous in both positions and no more safe 
from attacks of birds in one position than the-other.”’ 
Before considering the interpretation it may be of use to give some 
further evidence as to the attitude assumed by these butterflies on first 
going to rest. 
How Polyommatus icarus acts after dark I am not prepared to say, 
but of its actions before dark I can speak with confidence. For many 
years past I have made very careful observations as to the attitude 
towards dusk of this and many other butterflies. 
With P. icarus | have found only rare exceptions to the head down- 
ward position, and it was only after a long hunt that I was able to 
photograph an individual at rest with head uppermost. I especially 
remember observing the species in July, 1911, when it was extraordin- 
arily abundant in Hogley Bog, near Oxford. My son and I used to 
visit this locality four or five evenings a week during the whole of July 
and early August. Ican assert with the utmost confidence that at least 
99 per cent. rested head downward. ‘This was equally true whatever 
the object the butterfly was resting upon. Individuals of this species 
are often rather particular in the selection of a site. I have frequently 
- watched one, preparatory to settling down for the night, alight on a 
flower-head or grass-stem, turn head downwards, and then, after a little 
while, flutter off to another object, sometimes repeating the process two 
or three times before making a final choice. Many of them also open 
and close their wings before turning head downwards. This species is 
also to some extent gregarious, two or more often resting on a single 
stem or flower, and a score or more in the space of a few square feet. 
I experimented with them many times by touching them with my hand 
or with a grass-stem, and found that, when thus disturbed, they either 
fluttered off or more frequently dropped among the herbage, In the 
latter case they would presently crawl slowly up and, after settling 
down once more, would always turn head downwards again. Whenever 
I have met with this species in any number I have been careful to ob- 
serve its resting attitude before dark, and have found remarkably few 
exceptions to the above stated rule. 
Coming now to the interpretation of tne head downward position, 
my experience does not support Mr. Colthrup’s conclusion. In the 
usual attitude the bright orange spots of the hindwing are uppermost, 
and thus more conspicuous than if the insect adopted the reverse posi- 
tion. Furthermore, a less vulnerable point of attack is certainly pre- 
sented by the hindwings covering the short body concealed well within 
them than by the head projecting in front of the insect. It is also im- 
portant that injuries such as enemies would inflict have been frequently 
observed near the anal angle of the hindwing in otherwise fresh and 
undamaged specimens. The behaviour of another British Lycenid 
supports the above interpretation. I refer to Rwmicia phlaeas, which 
also usually rests head downwards, but is nothing like so consistent as 
P. warus. I have also experimented with this Lycanid and find that 
if alarmed, it does not drop down like P. icarus, but often thrusts forward 
the forewings and shews the black spots near their apex, thus exposing 
a directive mark to a possible enemy. After a while the forewings are 
lowered and the marks hidden beneath the hindwings. 
