The Male Genital Armature of the Dcrmaptera. 415 



in a few Neotropical forms. But nothing in a comprehensive way- 

 has been done since the appearance of Zacher's work. 



Although we differed on a number of points of detail, Zacher 

 and I soon found that, though travelling by different roads, we 

 were converging towards a common result. I had previously con- 

 fined my attention to purely external morphological characters, 

 but now set to work to make a comparative examination of the 

 male genital armature of as great a variety of species, and of genera, 

 as possible. 



I am consequently able to supplement Zacher's work very 

 largely, and to confirm or modify his opinions. The accumulation 

 of a much richer material than either Verhoeff or Zacher ever had 

 at their disposal, the preparation, study, illustration, and com- 

 parison, has taken a great deal of time, and as in the future I dare 

 not hope to have much time at my disposal, I venture to publish 

 these notes, incomplete as they are, in the hope that they will 

 stimulate other workers to enter the field, and carry on the progress. 

 The classification of the Psalinse in particular requires much study. 



It is with the object of drawing the genitalia that I have in 

 recent years impressed on my correspondents abroad the desira- 

 bility of preserving and packing their specimens in spirit ; it is 

 very important that spirit specimens should be kept in as great 

 variety as possible, for we are yet very far from the ideal of 

 possessing a good and careful drawing and description of the 

 genital armature of every known species of earwig. 



I am very much indebted to Lt.-Col. F. W. Winn Sampson for 

 the preparation of the slides, work which demands both skill and 

 time, neither of which I was in a position to employ myself. From 

 these slides I have made the drawings which illustrate this paper ; 

 they are I fear, very amateurish, and not uniform, but they have 

 the advantage of throwing into relief the points which I wish to 

 emphasize. There is great scope for investigation in the structure of 

 some of these complex organs ; I have begun, and hope one day to be 

 allowed to finish, a series of observations on the genitalia of 

 Di/platys under very great magnification, with the help and advice 

 of a trained histologist. But for the ordinary purposes of the 

 systematist, an ordinary microscope with 1-in. objective for general 

 examination, and ^-in for details, is quite sufficient. 



There is no difficulty in drawing out the genitals from a fresh 

 or spirit-preserved earwig ; if the large ninth sternite, or penulti- 

 mate ventral segment, be lifted, the parameres may be seen resting 

 in a little hollow, from which they may be drawn out with a fine 

 pair of forceps, and transferred to a small tube to await their turn 

 for staining, or they may be simply mounted at once in balsam. 



But in dealing with old and dried specimens, the difficulty is 

 greater. I find the simplest method is to break off the last two or 

 three segments of the abdomen, preferablv only the last two ; this 



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