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XII. On the structure of the terminal sefjment in some 

 male Ilcmiptera. By David Sharp, M.B., F.R.S., 

 F.L.S., &c. 



[Bead February 5th, 1890.J 



Plates XII., XIII., & XIV. 



The arrangement of the subjects is as follows : — 



1. Introductory. 



2. DescrijJtion of the i^arts in various species. 



3. Comparative observations on the separate structures. 



4. General remarks. 



I. Introductory. 



Although entomologists are now becoming acquainted 

 with the remarkable and complicated structures con- 

 nected with the organs of the male devoted to the fer- 

 tilisation of the eggs of the female, it is probable that 

 the subject has even yet not received so much attention 

 as it deserves, and as it will doubtless secure in the 

 future. There are several reasons for this comparative 

 neglect ; among them may be mentioned the extremely 

 complex and varied nature of the structures : this not 

 only renders them most difficult to describe intelligibly, 

 but also has hitherto made it impossible to homologise 

 the various parts seen in different insects, so that no 

 satisfactory system of nomenclature for them has been 

 established. To this may be added the great difficulty 

 that exists in forming any idea of their true function. 



I have recently been examining some heteropterous 

 bugs, and I have found these structures in them remark- 

 ably easy of examination, and to a certain extent, 

 perhaps, comprehensible as regards their function : and 

 as very little, so far as I have been able to find, has been 

 written about them, I have thought the following remarks 

 about a few Pentatomidie might possibly be of some 

 value, notwithstanding their very imperfect and desultory 

 nature. 



TRANS. ENT. SOC. LOND. 1890. — PART III. (SEPT.) 2 E 



