April 1, 1868.] 



HARDWICKE'3 SCIENCE-GOSSIP. 



77 



and plants containing larvae or pupae in the stems 

 are not difficult to carry away. 



To kill the captured insects it is only necessary 

 to immerse them in boiling water for a very short 

 time. They should not be left in it after their death- 

 struggle, but taken out with a camels'-hair brush 

 and placed on blotting-paper to dry. This does not 

 destroy or damage their colour or markings in any 

 way. A good way to get them out of the water 

 rapidly, and without handling them too much, is to 

 make a sort of strainer with a piece of muslin, which 

 is put into the hot water, and into which the captives 

 are then immersed. In this way all can be lifted 

 out at once and placed on the blotting-paper. It is 

 always as well to put the beetles out of the laurel 

 bottle also into the hot water, lest any spark of life 

 should remain. Those that are killed with laurel 

 are so stiff that it will be found impossible to set 

 them at once. They should be dried on blotting- 

 paper (merely to drain off the water), and put, with 

 all others which it is not convenient to mount at 

 once, into a muslin bag, which is to go into another 

 tightly corked laurel bottle, retained for relaxing 

 purposes — the effect of a stay in the latter for a few 

 days being that the insects can be most easily mani- 

 pulated. They may, indeed, remain in it for months, 

 or even over a year, but are in that case liable to go 

 rotten and greasy. 



The young and tender topmost shoots of the 

 laurel are best : they should be bruised, stems and 

 all, and cut up into little pieces. If damp when 

 gathered, laurel and beetles will go mouldy. 



To mount the specimens, all that is required 

 is good cardboard of fine surface and moderate 

 stoutness, some pins, a setting-needle (made by in- 

 serting the point half of a fine needle into a thin 

 paint-brush stick), a fine brush for setting, a larger 

 one (flat red sable is the best) for brushing out the 

 legs, a piece of flat cork to pin the card on, and a 

 bottle of gum-tragacanth. The latter can be obtained 

 at any chemist's, and should be selected of as trans- 

 parent a nature as possible. A few flakes of the 

 size of the finger nail, with one or two nodules of 

 clear gum-arabic, will make a good-sized bottle full, 

 — the gum not melting, but absorbing water, and 

 swelliug into a milky mucilage, which should be of 

 even quality, and so thick as not to flow readily. 

 Only a little need be made at a time, and a drop or 

 two of carbolic acid will prevent it from turning 

 mouldy. Another brush should be specially retained 

 for the gum-bottle, and a little clean water always 

 at hand when specimens are to be mounted. The 

 readiest way is to take a strip of card rather deeper 

 than the insect to be set, pin it on the cork, and put 

 some of the gum on the space the insect is to occupy : 

 the specimen (which has been turned on its back in 

 order that its legs and antennae might be brushed 

 out) is then put on the gum, and arranged with the 

 setting-needle and fine brush, care being taken not 



to gum' the upper surface. A pocket glass of 

 moderately low power will usually be needed for the 

 more exact performance of this operation. Perhaps 

 the best direction for the limbs is as follows : the 

 palpi straight forward ; the antennae sloped on each 

 side straight, at an angle of about 45 degrees ; 

 the front legs forward, parallel with the antennae, 

 and the middle and hinder legs parallel to each 

 other, and rather directed backwards: but the limbs 

 should not be straggled out unnaturally, nor the 

 different segments of the body unduly separated or 

 distorted, the main object being to get the body 

 strictly level and straight, and to display the limbs 

 (and where practicable the mouth-organs), so that 

 they can be readily examined with a higher power 

 when necessary. Many specimens can be mounted 

 side by side on the same strip of card, leaving a gap 

 between each ; or, if preferred, each specimen can 

 be mounted on its separate card. All superfluous 

 gum must be washed off the card (which it is some- 

 times desirable to damp on the lower side, to pre- 

 vent curling), and when dry, which will be in a week 

 or fortnight, according to the weather, the specimens 

 can, if set in a row, be cut up separately and evenly 

 the card being trimmed away close, and straight in 

 front and at the sides, but leaving a moderate space 

 behind, through which the pin is to be pierced. 

 Insects of the same species will, of course, have 

 their cards afterwards cut to exactly the same 

 length. When a specimen is refractory, it should be 

 left to dry on the gum, and in a quarter of an hour 

 or so it can be easily treated by damping and pulling 

 into position one leg, or all the limbs on one side, at 

 a time. A small pair of forceps, such as are used 

 with the microscope, is very useful for this purpose. 

 Stubborn limbs can also be held down with small 

 card braces on pins until the gum has dried. The 

 Brachelytra require very careful setting, as their 

 long, flexible, and uncovered abdomens run up in 

 drying. To avoid this, it is best to insert the point 

 of a fine needle into the extremity of the abdomen, 

 and pull out all the segments to their utmost ; this 

 breaks away the " intercostal" muscles, if I may so 

 pervert that adjective, and the abdomen can then be 

 put back to its proper length without much fear of 

 shortening. A very fine setting-needle for this 

 purpose is obtained by putting a sealingwax handle 

 to a "bead-needle." An extra application of gum to 

 the tail is also useful here. Specimens of both sexes 

 of each species will be, of course, mounted on their 

 backs, to show the under side. Large beetles (the 

 word large being construed according to individual 

 fancy) must be pinned straightly through the right 

 wing-case, near the shoulder, avoiding the articu- 

 lation of the middle legs. Their limbs can be dis- 

 played with pins or card-braces on a cork setting- 

 board. If beetles of large size be mounted on card, 

 their bodies should be fastened to it with white 

 liquid glue, obtainable at any oil-shop ; their limbs 



