42 



against them is ' many females crippled.' I take it that the crippling 

 was confined to the females, and the form of the crippling, as far as 

 my memory goes (and it is only memory), is that they had mis- 

 shapen wings, i e. pieces out of them. Their origin was doubtful, 

 and they had probably been inbred many times." 



The figure of Mr. Enock's specimen is of a male. A third instance 

 of this malformation occurred in the experience of Mr. E. R. Bankes, 

 and the specimens (all?) are in the British Museum ; they are females. 

 Mr. Bankes tells me that he "reared, July i ith to 23rd, 1904, thirty 

 dispar, among which were ' several ' with the curiously malformed 

 hind wings ; the rest were quite normal." They had been inbred at 

 least several years, and Mr. Bankes has ascertained nothing more 

 definite than that the original moths came from " America." 



Fernald and Forbush, in their larj^e volume on this species, make 

 no reference to such a malformation occurring, so it cannot be 

 common in "America." Mr. Bankes' specimens have a smaller 

 sector wanting than shown in the figure of Mr. Enock's specimen ; 

 it is more apical, and has a margin that is approximately an arc of a 

 circle (no angular notching). 



I seem to have some recollection of having seen somewhere else a 

 figure of this form of L. dispa?-, but if so, I have not been able to find 

 it again. 



Another example of such " mutation "-like variation is in a brood 

 of Pteros/otna palpina of which Mr. L. W. Newman has given me a 

 specimen. All this brood had very short broad wings. I suggest 

 the varietal name b?-evipennis by which it may be called. As com- 

 pared with an ordinary specmien taken at random, my specimen has 

 a fore-wing of 15 mm. from base to apex as against normal 25 mm., 

 with a width from apex to tornus of 12 mm. against 14 mm.; the 

 hind margin is very upright instead of the normal very oblique line, 

 due to the difference in length of the costa and hind margin being 

 much less than usual. 



It often happens that particular broods of some species bred 

 present several examples of anomalous wing forms ; but unfortunately 

 these are usually cast aside as not being " good specimens," and 

 remain unnoticed and unrecorded. As a recent occurrence, Mr. 

 Tonge has, amongst a number of H. dominula, bred this year, not a 

 few with irregular and asymmetrical wing forms, but several with 

 symmetrical abnormal wing forms that can hardly be other than con- 

 genital, as is probably the case with Mr. Willsden's specimen of 

 T. crepusailaria, figured in " Proc. S. Lond. Ent. Soc," 1906, p. 41. 



There can, however, unfortunately, be no doubt that, where any 

 definite history is wanting, it is impossible to assert at what period 

 of development the malformation arose, whether it was congenital, 

 /. e. from an early embryonic state, or from some later stage. Under 

 this doubt come many of the specimens I show you ; but there are 

 several where a wing is reduced in size and not otherwise deformed, 

 by interference with the pupa. For example, a specimen of Libythea 



