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y. On the Structure of the Lampyridae, ivith reference 

 to their Phosphorescence. By the Eev. H. S. 



GOEHAM. 



[Piead March ord, 1880. J 



The interest taken by the members of the Society who 

 were present when I rather briefly stated some morpho- 

 logical observations I had made while studying the 

 Lmnpijridce, was so much greater than I had anticipated, 

 that I think it worth while to lay before the Society a 

 fuller summary of those facts, and venture to restate in 

 a rather fuller form, and, if I can, more clearly, the con- 

 clusions at which I arrived. 



I think it will be admitted that generalisations founded 

 on a limited number of phenomena are only misguiding, 

 and have no sure basis, while in those founded on a large 

 number of facts, some cases are sure to be found, which 

 may at first seem adverse to the conclusion which we are 

 at last compelled to adopt. 



This has been the case here. There are examples, such 

 as the non-luminous species, which I do not profess to say 

 more about than that they do not invalidate the general con- 

 clusion at which I arrive, which is that the sexual instinct 

 has played a large part in moulding the external structure of 

 this group of beetles, and that it is to that we may look 

 for an adequate explanation of the wonderful development 

 of phosphorescent light, though perhaps not to its origin. 



In the first place, then, it is to be observed that all the 

 species of this family do not possess the luminous faculty 

 in equal degree ; but that on the contrary, while some are 

 highly luminous in both sexes, some are only highly so in 

 the female, some are not luminous in either sex, and some 

 (though this appears rather doubtful) are luminous in the 

 males, and not so, or much less so, in the female. 



The part which this faculty of emitting light plays in 

 the economy of nature has been long and earnestly debated. 

 The most general view, and therefore one to which I lay- 

 no claim for originality, but which my observations tend to 

 confirm, is that it serves as a beacon to attract the male to 



TEANS. ENT. SOC. 1880. — PART II. (jUNE.) F 



