42 THR entomologist's recoud. 



I look verticall}' I get a vertical view. In any case, when the organs 

 are in use, tlic f/cnitalia arc open — iu)t fihiit. 



Again, what advantage does the profile view give ? It shows the 

 contour of the ralrefi'^-, a side (and strictly limited) view of the tci/anien-'- 

 with its ring formation crashed (or often broken) and the penis''-. All 

 these points are equally or better shown by the vertical position, and a 

 great deal more. For Mr, Pierce and I have pointed out that the 

 valves, tegumen, and penis are not the " be all and end all " of the 

 matter, but that there are other structures hitherto neglected which 

 belong neither to valve, tefptuien, or penis. These structures arising 

 from the central area of the genitalia, between the valves, are entirely 

 concealed by the profile position, though they must be of the greatest 

 interest and importance. Reference to Petersen's Monograph upon 

 "The Genus I'^iipitJiecia" {Iris, Band, xxii., 1909) will illustrate my 

 meaning. 



In all his drawings of the single valves in pro/ile position, the 

 organs, which belong to the central area of the genitalia, are shown as 

 though part of the valve. The reason is plain. The imaginal 

 abdomen is cylindrical, but the two final segments are practically 

 hemi -cylindrical. In the profile mount the dorsal half cylinder must 

 be flattened, while the approximately fiat ventral surface must be 

 either " bulged " or crumpled up. The suggestion that the examina- 

 tion of the central area in the profile specimens may be attained by 

 the mutilation of the object, I cannot accept as scientific. Dissection 

 is all very well, and necessary, but it will not, in the present case, help 

 the observation of the organs in " a natural position." 



I do not wish to seem to undervalue the profile view. We get it 

 during the preparation of the object. Nor do I despise the profile 

 mount, which is very useful. But I do earnestly uphold the vertical 

 as showing more, and therefore more useful. 



And I further assert that the profile method of mounting is more 

 worthy of a beginner than of a competent scientist. It is vastly more 

 easy and more speedy. It requires less care, less patience. I would 

 undertake to instruct, any but the clumsiest youth, to prepare a pass- 

 able profile mount, in half-an-hour, I could mount thus as fast as 

 hand and eye could work. But it is not thus Science works. Witness, 

 for instance, the long patience of the Chemist, the Astronomer, the 

 Physicist, etc. 



In this matter I personally entirely disagree with " some of the 

 most able Continental insect Morphologists." Mr. Pierce and I can- 

 not be ignorant that " Systemists who are really eminent to-day do 

 not believe in the Study of the Genitalia " as an aid to their work. 



* I use these terms advisedly. 



Valve. Mr. Rethune-Baker accepts the authority of Dr. McDunnough, so do 

 I, here. Dr. McDuunough al'linns that this teini has been used from hrfare the 

 year JUIS, and gives the authorities. Amongst these is Durmeister, wlio aiiplied 

 the term, as does Mr. Pierce. " Clasper " seems to have come in with Scudder, 

 1870. 



Teguman. Reference to G. Buchannan White's paper and diagram {Trans. 

 Linn. Soc, ser. 2, Zool., vol. I., phite 55 ; figures 10, 11, 42) prove that he meant 

 by this term the whole circle or ring, except the " saccus," which, in his dried 

 specimens, ho could not set. 



Penis. " The greatei includes the less." 



Surely there can be no objection to an Author who corrects his previous 

 mistakes ? 



