32 



lantern slides, some of which have been reproduced in our 

 Proceedings. 



To recapitulate briefly, I will remind you that in this species in 

 the adult stage the light-giving property is practically confined to 

 the female. Destitute of wings, she is rather an unlovely object, 

 doomed to crawl about amongst the grass and low herbage, while 

 her prospective spouse enjoys the freedom of the air above her. Yet 

 her light is emitted from the underside of her tail, a situation that 

 would not at first sight appear to be particularly well chosen as a 

 source of illumination. Her iiiodiia opermuU in exhibiting her light 

 is usually to climb a little way up some convenient stem and to sit 

 there with her lamp suspended, her body twisted a little to one side 

 so as to exhibit the light without obstruction. If she can find no 

 stem stiff enough to bear her weight she will remain with her body 

 on the ground, the abdomen twisted to one side to expose the light 

 as freely as possible, turning it first tj one side then to the other in 

 her attempts to attract the attention of wandering males. At 

 Lugano Mr. Main and I have observed that they were particularly 

 partial to old walls, even sitting ten or twelve feet above the ground. 

 Though we found the larvae fairly plentiful in the grass the female 

 beetles were always on the walls, and in such a situation their light 

 was plainly visible from a long distance ; the twisting motion of the 

 abdomen was also clearly observed. 



Luminous organs are present in the male glow-worm in a similar 

 situation, but to a very minor degree. The extent to which they 

 are functional possibly varies in different localities; at any rate 

 Fowler quotes Mr. Dillwyn as saying that around Swansea he has 

 " not observed the small light in the males which is always 

 sufficiently obvious about Dover." In the New Forest, where I have 

 taken them on the wing in some numbers I do not remember ever 

 to have noticed any light, but my observations at the time were very 

 casual. It is probable that in this sex the light is emitted only for 

 a comparatively short time after reaching maturity, and that it soon 

 becomes exhausted. 



Photogenic organs are also present in an advanced degree in both 

 the larva and the pupa ; even the eggs are luminous, though there 

 is here no definite light organ, but the whole surface glows faintly. 



To the same family belong the "Fireflies" of southern Europe. 

 Of these there is a considerable variety of species, which possibly 

 present slight difterences in the details of their light emission. One 

 of the best known is Luciola italica of northern Ital}', a species 

 whose habits Mr. Main and I had the pleasure of studying at 

 Lugano. 



Luciola italica was observed on the evening of our arrival at 

 Lugano, in the grounds of the school, near the lake. We had seen 

 no signs of them at Baveno, but had scarcely an opportunity of 

 observing them, having been driven in early by the rain ; later that 

 evening we found them in the grounds of the Washington Hotel, 



