COLLECTING AND PRESERVING INSECTS. 89 



Small insects, especially beetles, may be mounted on cards 

 or pieces of mica through which the pin may be thrust. The 

 French use small oblong bits of mica, with the posterior half 

 covered with green paper on which the number may be placed. 

 The insect may be gummed on the clear part, the two sexes to- 

 gether. The under side can be seen through the thin mica. 



Others prefer triangular pieces of card, across the end of 

 which the insect may be gummed, so that nearly the whole un^ 

 der side is visible. 



Mr. WoUaston advocates gumming small Coleoptera upon 

 cards. Instead of cutting the i)ieces of cards first, he gums them 

 promiscuously upon a sheet of card-board. ''Having gummed 

 thickly a space on your card-board equal to, at least, the entire 

 specimen when expanded, place the beetle upon it, drag out 

 the limbs with a pin, and, leaving it to dry, go on with the 

 next one that presents itself. As the card has to be cut after- 

 wards around your insect (so as to suit it), there is no advan- 

 tage in gumming it precisely straigJd upon your frame, — though 

 it is true that a certain amount of care in this respect lessens 

 your after labor of cutting-off very materially. When j-our 

 frame has been filled, and you are desirous of separating the 

 species, cut out the insect with finely pointed scissors." 



For mending broken insects, i. e. gumming on legs and an- 

 tenna which have fallen off, inspissated ox-gall, softened with a 

 little water, is the best gum. 



For gumming insects upon cards Mr. WoUaston recommends 

 a gum "composed of three parts of tragacanth to one of 

 Arabic, both in powder ; to be mixed in water containing a grain 

 of corrosive sublimate, without which it will not keep, until 

 of a consistency just thick enough to run. As this gum is of 

 an extremely' absorbent nature, nearly a fortnight is required 

 before it can be properly made. The best plan is to keep add- 

 ing a little water (and stirring it) every few days until it is 

 of the proper consistency. It is advisable to dissolve the grain 

 of corrosive sublimate in the water which is poured Jirst upon 

 the gum." 



Preservative Fluids. The best for common use is alco- 

 hol, diluted with a little water ; or whiskey, as alcohol of full 

 strength is too strong for caterpillars, etc., since it shrivels them 



