1913.] §1 



sucli a suggestion, as the condition would of course necessitate the 

 continuous inbreeding of species, which we know Nature takes every 

 precaution to prevent. It is as necessary for these winter G-eometers 

 to be distributed as it is for any of the summer species, and that they 

 are distributed in various ways, but chiefly I think by the method I 

 have suggested on p. 63 of the March number of this journal, there can 

 be no doubt. 



Elm Lea, Dalton, Huddersfield .- 

 March 6th, 1913. 



APTEEOUS FEMALES OF WINTEE MOTHS. 

 BY T. A. CHAPMAN, M.D., F.Z.S. 



Mr. Porritt is quite right when he says that I have no suspicion 

 that the apterous ? ? of winter moths are carried by the J (^ . There 

 was however a time when I did eiitertain the suspicion. Mr. Porritt's 

 statement that he thinks it well-founded makes it useful to review the 

 position. 



On two occasions many years ago, memory fails me as to probably 

 others, I set myself to catch as many (^ ^ oi C. hrumata on the wing 

 as I could, their abundance at the time suggesting such an investigation. 

 I have no recollection how many S S '^ caught, but it was a very 

 considerable number, certainly more than one, possibly several, hundreds. 

 Amongst them was not one ? . This emphasised my fi]-st and initial 

 difficulty in adopting the suspicion, viz., that were it well-founded we 

 should have, not a few doubtful, but plenty oi well-verified observations 

 of the fact. They are practically quite wanting. 



Insects of various orders fly about when paired, especially, I think, 

 Biptera. But with Lejndoptera the tendency and habit is to sit quietly. 

 This does not prevent one often seeing them on the wing, but I believe 

 always after being disturbed in someway. The amount of disturbance 

 may be slight, so slight in the case of some butterflies that one often 

 takes such flight as a usual habit. Such butterflies (I hazard guesses 

 rather than facts here) are probably those that do not remain long 

 paired, and, resting on herbage, are in some danger from grazing 

 animals. Those butterflies that hide away when paired, such as the 

 Vanessas, are not often seen paired at all. There is no scrap of 

 evidence that I know of that such paired flight is towards the food- 

 plant, and I do not think I have often seen such pairs attracted by 

 flowers. The occurrence of the larvae of these moths on comparatively 



