33 
more rosy, but representing upperside markings of same part; atalanta, 
with added blue, ochreous, and white, but representing colours and 
markings of upperside otherwise. 
(ii.) Aijlai* (urtieae, etc.) with a heterologous crypton of a special 
colour (greatly diluted upperside colour ? or greatly demelanized 
underside colour ? or some other origin and with some of upperside 
markings reproduced). 
(iii.) Euvanesm polyyonia with homologous crypton ; or almost 
(Yamuna euyonia) homologous crypton. 
The classification is merely intended as a rough reference for the 
purposes of this discussion. But possibly our use for some elaboration 
of distinctions may depend on our desire for accuracy of phrase as 
regards positions assumed by butterflies. One would suggest that it 
is not enough to observe that the wings are closed, to leave visible 
underside markings only, irrespective of the butterflies purposes, 
irrespective of that amount of the upperwings underside that is 
visible, and call that position rest. There are so many conditions of 
“rest,’ so many under which, that is to say, butterflies apply the 
“ closure.” It is questionable if they do not when sunning themselves 
with more or less outspread wings in some degree, “rest”; but apart 
from this :— 
(i.) After a long flight, (ii.) in intervals of feeding, (iii.) in intervals 
of clouding over sun, or even (iv.) in intervals of courtship, a condition 
of closed wings may occur ; but none, at first, at any rate at all 
commonly, will be found exactly to conform, as to exact pose of wings, 
to position of sleep; and one item in the last will certainly be absent, 
viz., the alignment with the body of the antennas closely pressed 
together, to say nothing of the considerable raising of the body and 
hindwings from the support. 
Without the expression of such details the position is not that 
of sleep. It is questionable whether it is advisable, therefore, to use 
the term rest for any but the temporary conditions and to carefully 
define the latter condition as the position of (v.) sleep. They ought 
to be carefully distinguished; as instances of these may be cited V. to, 
in which the attitude taken upon first alighting for rest, with hind- 
wings largely biding the forewings, slowly, sometimes jerkily, is 
changed to position of sleep, with underside of forewings largely 
exposed, cf. also V. c-album. And as instance of many others, T. 
betulae, in which opposite is the case ; I have never been able to sur¬ 
prise the few examples of these that I have observed with antennfe 
separated and upperwings completely dropped behind hindwings. On 
least arousing, upperwings are somewhat raised from behind hind¬ 
wings, and the antennas, separated, are slightly raised at same 
moment. 
Then (vi.) there may well be special attitudes of apprehension of 
differing degree ; and without observation it is impossible to say that 
the attitude of sleep is, or is not, closely approached by positions 
produced by other conditions, and different species will vary, closely 
allied species may vary. As regards such attitudes of apprehension, 
definite movements of wings may be noticed in E. ianira J . Sitting 
more or less near the ground, and more or less outspread, perhaps 
courting, or calling, or perhaps sunning herself, she is aware of some 
movement around. 
xix. 
