60 [March, 



(2), sent by Mr. Cockerell, and find them to agree in every way with my A. cocoiis 

 (vol. iv, p. 186), which I still believe to be distinct from the A. destructor of Signoret. 

 The entire absence of grouped glands, and the double row of marginal " wax ducts " 

 or pores in my twenty types of A. cocotis, are, I think, sufficient distinctive charac- 

 ters to separate it from A. destructor, Sign. It is just possible, however, that 

 Signoret, Cockerell, and myself have examined different stages of one species ; if so, 

 it will account for the variation of character noted ; but this must be proved beyond 

 doubt before my species can sink. — R. Newstbad : October 11th, 1893.] 



GREASE: 

 DO MALE MOTHS REQUIRE MORE ENERGY THAN FEMALES? 



My best thanks are due to Dr. Richard Freer for his kindly criticism of my 

 paper on the above subject. It is by discussion that the wheat is sifted from the 

 chaff, and the truth revealed. It often happens, too, that side issues crop up of even 

 greater importance than the original topic ; and thus are new ideas developed, and 

 fresh channels opened up for thought. 



Dr. Freer and I are agreed on many points, but there are one or two on which 

 our opinions widely diverge, the chief of which is the question as to whether males 

 have a greater necessity for energy than females. Dr. P. mentions Messrs. Geddes 

 and Thompson's theory about the " Evolution of Sex " (by nutrition and temperature) 

 as being fatal to mine. It is just about twenty years ago that I penned a few lines 

 on a similar theory (Ent. Ann., 1874, p. 152). Speaking of the more noticeable 

 papers of the season, I wrote as follows : — "but, as Alice would say, the 'curiousest' 

 paper of all is devoted to the subject of controlling the sexes by a process of starva- 

 tion (the starvelings being males, and the healthy well-fed examples females). When 

 it is taken into consideration that the writer is a lady, the whole affair looks very 

 like a satire on the male sex generally." This article, by Mrs. Mary Treat, which 

 was published in the " American Naturalist," vol. vii, p. 129, is endorsed by Messrs. 

 Geddes and Thompson. 



Still, though the theory is against me, the facts are for me. Take the following 

 extract from Messrs. Geddes and Thompson's book, page 16 : — " Let us begin with 

 an extreme yet well-known case. The cochineal insect, laden with reserve products, 

 in the form of the well-known pigment, spends much of its life a mere quiescent 

 gall on the cactus plant ; the male, on the other hand, in its adult state is agile, 

 restless and short lived. Now, this is no mere curiosity of the entomologist, but in 

 reality a vivid emblem of what is an average truth throughout the world of animals 

 — the preponderating passivity of the females, the predominant activity of the 

 males." Now, the reason of this excessive activity of the males is, to my fancy, a 

 salutary provision for the healthy perpetuation of the species (see my remarks on 

 the subject, Ent. Ann., 1867, page 130). 



Yery well ; activity cannot be kept up without force, nor force without fuel. 

 Whence, then, comes this force ? Surely, the answer must be, from the fuel food, of 

 which, all collectors are painfully aware, the freshly emerged males, of vigorously 

 flying species, contain such a superabundance. Dr. Freer has likened moths to man, 

 but a more familiar illustration of both is the steam engine, since each (moth, man 



