302 Dr. T. A. Chapman on 



In other species, not always very small, the insect may 

 be on a horizontal surface; but the wings are held up 

 vertically, and seem stiff enough to maintain this attitude 

 during drying. 



When the wings are dry and stiff this attitude is left, 

 and the wings take the resting position normal to the 

 species. What I have observed is, that this is not a 

 strictly correct statement of what occurs in certain species, 

 but that, by way of " recapitulation," the wings are de- 

 flexed to the position characteristic of the group (family ?) 

 to which it belongs, and later assume that belonging to 

 the species itself. I noticed this fact in the case of Acidalia 

 virgularia (Eois incanaria). So soon as the wings are 

 dry, in the attitude with them closed dorsally, they are 

 brought down to the surface on which the insect is rest- 

 ing, to the normal Geometrid attitude, with the inner 

 margins of the wings parallel to the body. This position 

 is maintained for a varying period, apparently so long as 

 the insect remains undisturbed ; in one instance, I noted 

 as long as three hours and three-quarters, and it may be 

 they often rehiain so till the evening flight. But if dis- 

 turbed, the insect runs or flies, even as little sometimes 

 as, say, half an inch, but settles down with the wing in 

 the Acidalian position, viz. with the fore- wings well for- 

 ward, showing a good portion of the hind-wing. This 

 occurs even if the disturbance is only a few minutes after 

 the wings are deflexed, and in no case is the Geometrid 

 attitude afterwards assumed. The explanation that this 

 was a case of "recapitulation " seemed quite probable; 

 if it were so, then it might be observed in some other 

 species. Unfortunately material for making further ob- 

 servations was not abundant, and, for instance, it did not 

 occur to me, in time, to secure some pupae of Smerinihus, 

 though I have a dim recollection, but no notes to say 

 whether this is reliable or the contrary, that the position 

 with the hind- wings well forward, in this and in some 

 Lasiocampids, is not assumed till some time after the 

 wings are dry. I had, however, several species of Ephyra 

 (Leucopthalmia), and found that their habit in this matter 

 was precisely the same as in E. incanaria. I also had pupae 

 of Selenia bilunaria, which seemed to be a desirable species 

 to observe, as its resting attitude is that of the butterflies, 

 and therefore less like the ordinary Geometrid position 

 than that of the Acidalias. I found that, in bilunaria. 



