6 BULLETIN 48, UNITED STATES NATIONAL MUSEUM. 



much curved,- for uiiug a very distinct "scoop-out." Opposed to tliis is 

 a movable tiiiger-like i)rocess, with hooked bristles at its tip, supple- 

 mented by two or even three other less specialized processes. 



What is the purpose of all these specializations, and why have they 

 been developed? 



To the latter part of the question I have no answer, save as the struc- 

 tures are sensory in character. It is usually conceded that the olfac- 

 tory orgaus and the sense of smell are situated in the anteun;v, and 

 that the developmeut of pectinations and sensory hairs is necessary to 

 enable the male to lind the female more readily. This explanation nuiy 

 be consulered as correct, but it gives uo reason why so simple a struc- 

 ture auswers the purpose iu the one case and why so extremely com- 

 plicated an apparatus should be re(]uired in the other. The sense of 

 touch is also placed in the antennre by students, and also without 

 doubt, so far as 1 am concerned, correctly. I would, however, in cases 

 of this character consider it rather a sense of appreciation than a sense 

 of touch, and possibly this sense of appreciation may cover those of 

 touch and hearing, being reduced to an appreciation of certain disturb- 

 ances in the atmosphere acting ui)on the extremely sensitive hair, which 

 communicate, directly or indirectly, with nerve fibers. That they are 

 not re(juired by the species to maintain its existence is i)roved, of course, 

 by the fact that the female has no such sensitive or sensory structures, 

 and hence we assume that they are of use in recognizing the presence 

 ot that sex by the male. 



Tlie other processes stand on a different iboting. They are mechanical, 

 not sensory in their cliaracter, and we assume that they have a sexual 

 function for the reason above given — they are found in one sex only. I 

 have never myself seen any species of this series iu copulation, nor 

 have I found any who have seen it. So far as I am aware, no publication 

 to which I have had access has described the process ; hence the subject 

 is one for conjecture. Judging from what we know of certain species of 

 Coleoptera these mechanical modifications are clasping organs, enabling 

 the male to encircle and tightly hold the female antennae during copu- 

 lation. Why the necessity for such organs exists in the present series 

 still remains a question. 



The most interesting modifications, however, are those of the male 

 forelegs, and in this entire tribe not a single species has a quite normal 

 structure of this member. Irrespective of all tuftmgs, the proportion 

 of the parts becomes changed. 



The coxa, usually not mobile but rigidly applied to the thoracic mass, 

 becomes movable, loses rigidity, and gradually becomes elongated and 

 attenuated, forming a functional part of the leg. 



The trochanter, which is inconspicuous normally, tends to increase in 

 length until it exceeds the femur in size in every dimension, giving us 

 a very distinct additional member in the leg structure. No specializa- 

 tions of a sensory character are developed on this segment so far as 

 our sj)ecies are concerned. 



