HELIOTBOPISM 
551 
and Precis clelia the diminution of the shadow when the wings are 
closed helps to conceal the butterflies from their enemies I have no 
longer any doubt. 
Further observations will show how far the habit is general 
within the families in which it has been observed, and whether it 
prevails in other families. 
In the discussion which followed the reading of this paper 
(March 7th, 1906), the President (Mr. F. Merrifield) threw out the 
suggestion that possibly the object of negative heliotropism might 
be to enable the butterfly to see to the greatest advantage. This is 
in agreement with Mr. Marshall’s remark that orienting butterflies 
are always very much on the alert. 
Dr. T. A. Chapman said that the heliotropic attitude, with tail to 
the sun, was familiar to observers of Vanessas and other Nymphalines, 
and some other butterflies of the European fauna. During their 
active period, when settling, usually on the ground, the butterflies 
in question assumed that orientation, and spread their wings flat on 
the ground with the head a little raised, making the greatest display 
of their colours, but chiefly appearing desirous to secure as vertical 
a sun as circumstances allowed; this might be different in the 
tropics. 1 
To this explanation Professor E. B. Poulton advanced an objec¬ 
tion, that when the orienting butterfly closed its wings the exposure 
of both body and wings to the sun’s rays is reduced to a minimum . 
Observations in the W. Indies , 1906-7. 
Constant Spring, Jamaica, January 8th, 1907. Precis lavinia, Cram., 
f. zonalis, Feld. Hot uncommon, but hard to catch; usually 
settled on the ground with wings open; seen to orient and to 
put its wings up, causing little shadow; seen also to adjust 
itself after settling, so as to make the orientation more perfect; 
but sometimes seen to face the sun. 
Maraval, Trinidad, December 19th, 1906. Anartia amalthea , Linn. 
Flies near the ground; settles with wings three-quarters open ; 
orients, but not always. 
Same place and day. Anartia jatrophae , Linn. Has a ghostly flight; 
settles on the ground; orients. 
Colon, Panama, December 28th, 1906, A. jatrophae . This species 
orients, but not very regularly. 
1 Proc. Ent. Soc. Land., 1906, p. xxvii. 
