5254 Insects. 



Capture of Deilephila Galii in Sussex. — It may perhaps interest some of the readers 

 of the 'Zoologist' to hear that on the 6th of this month I took a specimen of the 

 "scarce-spotted hawk-moth" of Westwood's ' British Moths/ vol. i. p. 18. My atten- 

 tion was attracted hy the loud humming caused by its wings, for it was too dark to see 

 the insect; but I could just see that a flower of the Verbena was shaking, and swept 

 it into my net. This was at half-past eight p.m. It was very violent, but succumbed 

 instantly to a small piece of cyanide of potassa in a drop of vinegar. I add this, as it 

 may be a useful hint to some of your collecting readers. I do not claim the 

 discovery of the use of cyanide of potassa for destroying insects, the credit belonging 

 to my friend G. B. Buckton, Esq. — Wm. Borrer, Jun.; Cowfolcl, Sussex, August 11, 

 185(5. 



On the Use of the Anal Fork in the Larva of the Puss-moth (Cerura vinula). — I 

 have two caterpillars of the puss-moth, which have just passed through their last 

 moult. One of these had moulted about ten hours, and had just began to eat after 

 the change, when I went into the room with a candle (as it was night) to look at him. 

 I must premise that they were kept in a large, wide-mouthed glass jar, with a cover 

 laid loosely on the top. The one I speak of had mounted on the edge of a large 

 poplar leaf, and was so close to the top that in lifting off the cover I slightly touched 

 his head. I was not looking at his tail at the moment; but, an instant after, I saw 

 projecting from the extremity of each branch of this forked organ a crimson filament, 

 as fine as a hair, but flexible and bent downward. When I first saw these filaments they 

 were projected about one-sixth of an inch from the tail-tips, and were in process of 

 being retracted into them, which in a few seconds was quite effected, no trace of their 

 presence remaining visible, except that the extremities of the sheaths, when examined 

 with a lens, were truncate and evidently perforate. It seemed as if the process was 

 one of direct and simple withdrawal of the thread, and not of involution; but, from 

 the tenuity of the filaments, I cannot be quite certain of this. The analogy of the 

 organ, and of its mode of use, with the Y-sbaped, orange-coloured, protrusile fork 

 in the neck of caterpillars of the genus Papilio struck me at once. The throwing up- 

 ward of the tail, as if to repel the affront, was exactly like what I have seen Papilio 

 larva? do with the head at the moment of extruding the fork. In the latter case, 

 however, the organ is distinctly everted and inverted. I tried several times afterward 

 to induce the puss to show fight again, coming suddenly upon him after intervals, and 

 insulting him in various ways; but no: he remained obdurate. — P. H. Gosse ; 

 August, 1856. 



Postscript. — I have since found that by tapping the glass jar with my finger-tips, 

 or by taking out the leaf on which the caterpillar rests, in that uncouth fashion that 

 was once upon a time considered lion-like, and laying it carelessly on a table, I can 

 make him protrude his threads at pleasure. Sometimes only one filament appears, 

 but much more commonly their motions are concurrent. The crimson filament, of 

 about the thickness of a horse-hair, is shot forth rather suddenly, to the length of 

 about three-eighths of an inch, from the tip of each of the tapering and muricated 

 anal processes. These are usually at the same moment thrown apart, and also jerked 

 over the back towards the head. The filament bends downward as it protrudes; and 

 when it has attained its utmost extension it begins instantly to be withdrawn, often 

 curling up in an irregular spiral as it disappears. When watched with a lens the 

 process is seen evidently to be one of eversion (for extension) and inversion (for with- 

 drawal) ; the most basal portion (about a line in length) is of a greenish white hue, 



