IIARDWICKE'S SCIENCE-GOSSIP. 



35 



cleavage-planes of any area, it would be necessary to 

 make a repeated number of observations. 



I may mention that the beds, a, 1/, in grain are 

 very like the bed a (fig. 30), but darker, and with 

 brown patches visible to the naked eye. The 

 cleavage-planes are nearly as wide apart as in a. 

 The beds b, c, &c, appear very like the beds a, &, in 

 composition and grain, but are less dark than the 

 latter, and the cleavage-planes are wider apart. 



E. Halse. 



PRESERVING LEPIDOFTEROUS LARVAE BY 

 INFLATION. 



By W. Finch, Tun. 



ALTHOUGH the method for preserving larvae for 

 the cabinet may be well known to many 

 -entomologists, there may be some of our readers to 

 whom the method, simple as it is, may be unknown. 

 Specimens are sometimes seen preserved in bottles of 

 spirits ; but these seldom form very beautiful objects. 

 These also cannot be arranged side by side with the 

 imagos in the cabinet. Therefore, to be able to 

 preserve the larvae, so that they may be placed in the 

 -cabinet, with their imagos, will doubtless be a source 

 of pleasure to many a tyro-lepidopterist. And as 

 the season is advancing when lepidopterous larvae 

 may be obtained in abundance, I offer these few 

 remarks as to the apparatus required and the method 

 of using it. 



Take a wide-mouthed bottle, of say two or three 

 pints' capacity (a jam-bottle does admirably), into the 

 neck of which fix an indiarubber bung, tightly ; bore 

 two holes through this, one on each side, and about 

 J inch from the edge. Now take a glass tube, to 

 fit one of these holes, and on one end of it fix 

 a piece of zinc (we will say the tube is J inch 

 in diameter, then the zinc will be about ij inch 

 long, by § inch wide), through the end of which 

 you have drilled a hole g inch in diameter, this 

 hole must come under the hole of the glass tube. 

 After drilling, rub the zinc smooth, on both sides; 

 then fix to the glass tube, by means of sealing-wax, 

 making the joint perfectly air-tight. Then affix to the 

 .zinc, at the opposite end to the hole, a strip of oiled 

 silk (on the under-side, of course), so that one end 

 forms a flap, loosely covering the hole. On sucking 

 at the other end of the glass tube, it will be found 

 that this flap of oiled silk forms an excellent valve, 

 through which no air can pass whatever. Now 

 thrust the other end of the glass tube through the 

 indiarubber^bung from] the under-side (removing it 

 from the bottle for this purpose, and refixing it). On 

 to the projecting end of this tube (the valve, of course, 

 is inside the bottle) affix an indiarubber tube (of any 

 length), having at its other extremity a hollow ball . 

 these tubes with ball affixed may be bought at the 



chemist's for about one shilling and sixpence. Now 

 we have a capital air-pump, by means of which the 

 bottle may be filled to bursting-point, on stopping up 

 the other hole in the bung. The indiarubber ball, I 

 should have mentioned, should have a small hole 

 bored in it, so that it can fill itself from the outer air, 

 as it cannot possibly draw any air out of the bottle, 

 because of the valve. By placing the thumb on this 

 hole, and squeezing the ball, a current of air is forced 

 down the tube and through the valve (which closes 

 again immediately) into the bottle. Now into the 

 other hole in the bung thrust a glass tube similar to 

 the one mentioned before ; but this need only enter 

 the bottle about two inches, whilst the other should 

 nearly reach the bottom. On the outer end of this 

 latter tube fix a short length of indiarubber tubing, 

 into the other end of which fix the tube with which 

 to inflate the larva;. This should be of glass, drawn 

 out to a point at one end, by means of melting it over 

 the gas. You should have several of these tubes, of 

 various thicknesses, according to the size of the 

 larvae to be preserved. Now, the inflating apparatus 

 completed, what shall we do to dry the skin of the 

 larvae, while inflated ? Take a tin canister, clasp a 

 band of iron wire on it, and fasten this to a wooden 

 stand of any kind, taking care that the canister does 

 not touch the wood at all, as it would burn it. Leave 

 the lid of the canister on, so that if the solder (where 

 the tin is joined) should melt with the heat, it will 

 not come to pieces. Cut a piece out of the tin lid a 

 little larger than a florin, and then you have a 

 capital oven. Get a small glass lamp from the 

 chemist's (cost is.), some wick'and spirits (methylated), 

 and set to work in the following manner :— 



Take your larva which you wish to preserve, put 

 him into a small vessel, with enough spirits to cover 

 him. Next trim your lamp and light it, place it under 

 the oven, to get it ready heated (you will soon find 

 out the exact heat necessary) ; your larva will by this 

 time be dead ; take him out of the spirits and lay him 

 on a sheet of blotting-paper, turn him about a little, 

 so as to get rid of all superfluous moisture, then take 

 a pen-stock, or anything round, and of similar thick- 

 ness ; and commence to roll out the viscera, or his 

 inside ; commence near the anus, to get a good start, 

 this prevents bursting. When you have rolled all the 

 contents of the body out from the head, the whole 

 length of the body, then insert the pointed end of 

 the blowpipe into the anal orifice. I should previously 

 have told you to clasp a bit of watch-spring round 

 this end of your tube, bending it so that it nips 

 tightly on to the pointed end, so as to hold the larva 

 on, as the pressure of air would otherwise blow it off. 

 Fix the watch-spring over the last pair of legs, and 

 then commence to pump air into the bottle, by means 

 of the ball, and soon the larva will become extended 

 in a natural manner. Do not force too much 

 air into the bottle, or the larva will be extended 

 to the full extent of its skin, and look an unsightly 



