310 THE entomologist's kecord. 



where given, accept them, and I have, somewhat unwillingly, to retain 

 my " Scotch attitude." 



I by no means, accept the proposition that no other theory can 

 possibly supplant the present ones, or that no other theory is 

 possible, on the contrary, I rather look forward to the time when 

 some future Darwin will give us the true explanation of these mimetic 

 resemblances and some future Huxley exclaim " how extremely 

 foolish of us not to have thought of that before." — (Lt.-Col.) N. 

 Mandeks (R.A.M.C, F.E.S.). 



The " stridulation " of Cychrus rostratus.— A chance remark 

 of Mr. J. Collins of the Hope Department, University Museum, 

 Oxford, who said he had caused dead examples of (_ j/chnis rostratus to 

 " stridulate " by pressing the abdomen, tempted me to look up my 

 published notes on Coleoptera, when 1 was surprised to find that I had 

 not recorded certain views on this question that occurred to me as far 

 back as the spring of 1907. 



Early in 1906 (hJnt. Beconl, 1906, p. 73) I published a note on the 

 stridulation of Cijclinis, when I said the noise was caused by muscular 

 movements of the abdomen near the apex, and that if one holds the 

 beetle by the fore-finger and thumb, the thumb on the underside of 

 the abdomen and the finger pressing the elytra down, it seems to lose 

 its power of producing sound. I then came to the conclusion that the 

 stridulation of the species was caused by friction between a certain 

 part of the abdomen and the elytra. In the same note I recorded the 

 stridulation of four females and the non-stridulation of two males. 



No true stridulating organs have been found. 



In the spring of 1907 I found two females of ('ifchmstit Corbridge- 

 on-Tyne and repeated the observations. The " siridulating " sound 

 was distinctly caused by an upward muscular movement of the 

 abdomen, but this movement seemed to me to be a wave movement 

 tending distally, and, remembering the structure of the elytra which 

 are soldered together and have the edges laterally folded over the 

 abdomen, it immediately occurred to me that the sound was not 

 produced by stridulation but by the compression of air between the 

 upper surface of the abdomen and the elytra, and its subsequent 

 ejection. This is, I believe, the true explanation of the " stridulation " 

 in Ci/rhriis rofttratiis, and one which satisfactorily explains the lack of 

 stridulating surfaces, though it does not account for the female alone 

 producing the sound, if indeed, the property is vested in the one sex, 

 as my previous observations would seem to suggest. — Richard S. 

 Bagnall (F.E.S.), Oxford. Norenihn- Wth, 1913. 



J^^OTES ON COLLECTING, Etc. 



Manduca (Acherontia) atropos at Chichester. — A specimen of 

 Mandiica {Acherontia) atropos was brought me on October 17th last. 

 It is a female, small, but perfect, and of dark, handsome colours and 

 markings. — Joseph Anderson, Chichester. 



CoLiAs EDusA IN LATE OcTOBER. — It may be of interest to some of 

 your readers to note that I saw a fresh male Colias edasa on October 

 25th last, flying along the road between Bramber and Hentield, 

 Sussex, but having no net was unable to secure it. — H. Baker-Sly 

 (F.E.S.), Horley, Surrey, Nm-einber. 1913. 



