39^^ Scent Glands in Lcpidoptera. 



on the sheet, in frantic activity, is a wonderful sight. But why should the 

 insects go to the sheet and not to the light ? My belief is that the wind 

 carries the vibrations made by tlie light on the the sheet, which retards 

 their progress into space and consequently causes a congestion, and it is 

 into the congestion that the moths come ; moreover large species like 

 Smerinthits ocellatus, the line of flight of which can be followed by the eye, 

 seem to come fixjm the region behind the- sheet, which is not illuminated 

 by the lamp. When they arrive over the sheet they describe a quick 

 curve in the air and alight with a crash among the grass at the foot of the 

 sheet. Another peculiaiuty is that most of the species that come have 

 a certain antic of their own, which every individual performs on arrival, 

 and generally keeps up all the time it remains. A few species, however, 

 come very quietly and take up a position of repose at once. 



Any other explanation than the one given I have failed to discover. 

 In case there was no sheet, then the moths would fly to the lamp, because 

 apparently the lamp would be the centre, and therefore the place where 

 the vibrations would be strongest. In the event of this theory becoming 

 an established fact, then this relationship of things would compel a 

 serious recognition of the possibility that when male moths visit light the 

 action is associated with emotional impulses. But even then the males 

 of apterous female species would again present a difficult problem as they 

 are frequent visitors to light. 



There now remains the problem of males visiting a box which encloses 

 a virgin female. We know that the walls of the box would greatly retard 

 the dissemination of scent, but what effect would they have on vibrations ; 

 are they known to pass through solid substances ? This is an important 

 question. 



This discussion is now taking on a feature which personally I think 

 is incompatible. The vertebrate and the invertebrate are too widely 

 separated biologically for points out of one order to be used to prove 

 problems in the other. It must be remembered that the biological 

 structure of female moths only allows one period of gestation, and not 

 successive periods as in mammals ; moreover, moths have antennae and 

 not noses like cats and dogs, and notwithstanding the noise made by the 

 Death's Head Hawk Moth, it is absolutely impossible for it to articulate 

 cries of emotion as wild beasts and birds do. 



B. MoRLEY, Skelmanthorpe. 



I am glad Mr. Morley has been able to record a single instance of the 

 pairing of lepidoptera in the spring. I had in my mind the statement 

 that Vanessa itrticce pairs in the spring when I wrote the note, and my object 

 was to bring out an absolute fact in support of the belief. Mr. Morley 

 is not so convincing in his outside references. My friend, Mr. Sheldon, 

 captured his Peronea cristana in the New Forest, and sleeved up both sexes 

 in the autumn, but he does not say that he ever saw any moth paired 

 either during the autumn or spring. Likely enough the females had al- 

 ready paired before he took them. And of the Xylina semibntnnea Mr. 

 Thornhill states distinctly that although he kept the captured male and 

 female together from autumn to spring, he never saw them paired. I 

 cannot at the moment put my hand on the note on Hopovina croceago, 

 although I know I have it somewhere. But in that case also, as far as I 

 remember, it was a matter of surmise, and I believe that practically all 

 females of the species captured in the early spring lay fertile eggs. I 

 am not at present going to discuss Mr. Morley's further notes on vibration, 

 although a good deal might be said. It is a rather ' far cry ' to shift the 

 supposed attraction, through vibration, by the moths, to that of light 

 in street and other lamps ; and I will only say that I no more believe that 

 efficient vibration can come through the glass of a lamp than it can through 

 a wood box. The theory is too ' far fetched,' and to my mind utterly 

 absurd. — G. T. P. 



Naturalist, 



