Collecting and Rearing Insects 657 



mouthed bottle from three to six inches high (a quinine or quassia bottle is 

 good) and covering this with wet plaster of Paris. When the plaster sets 

 it will hold the cyanide in place, and allow the fumes given off by its gradual 

 volatilization to fill the bottle. Or the cyanide may be covered with damp 

 sawdust over which is placed a cardboard disk cut so as to fit tightly into 

 the bottle. The advantage of the sawdust covering instead of plaster of 

 Paris is that it allows one to clean out the bottle after the cyanide is used 

 up and to recharge it. The plaster of Paris is broken out of a used-up bottle 

 only with difficulty. The disadvantage of the sawdust and cardboard cover 

 is that it is likely to be loosened if the bottle is jarred often. Insects dropped 

 into a cyanide bottle will be killed in from two to six or seven minutes. Keep 

 a little tissue-paper in the bottle to soak up moisture and to prevent the 

 specimens from rubbing. Also keep the bottle well corked. Label it 

 "poison," and do not breathe the fumes (hydrocyanic gas). Insects may 

 be left in it overnight without injury to them. 



Butterflies or dragon-flies too large to drop into the killing-bottle may 

 be killed by dropping a little chloroform or benzine on a piece of cotton, 

 to be placed in a tight box with them. Larvae (caterpillars, grubs, etc.) 

 and pupae (chrysalids) should be dropped into the vials of alcohol. 



When the collected insects are killed they may be "pinned up" or 

 "papered" in the field; or if not many have been taken, may be brought 

 home in the killing-bottle and cared for after arriving. 



To "paper" specimens and only insects with large wings, as butterflies, 

 moths, dragon-flies, etc., are papered they should have the wings folded 

 over the back and the specimen then laid on one side on a rectangular piece 

 of smooth paper, not too soft, which is then folded so as to form a triangle 

 with the margins narrowly folded over to prevent its opening. A very success- 

 ful professional collector of my acquaintance "papers," in a sense, small 

 insects in the following way: In the bottom of a small tin, wooden, or paste- 

 board box he puts a thin layer of glazed cotton; over it he lays a sheet of 

 paper, and on this a layer of small insects just as they are poured out of the 

 cyanide bottle; then a covering sheet of paper, and over this a layer of cotton, 

 another sheet of paper, a layer of insects, and so on. In this way he rapidly 

 cares for hundreds or thousands of specimens in the field. When these 

 specimens are brought home he either pins them up immediately while 

 fresh and flexible, or stores them away to be worked over and pinned up 

 at leisure. Before dried insects can be pinned, however, they must be re- 

 laxed. This may be effected by steaming them, or simply by putting them 

 for a day or two into a closed glass jar with a soaked sponge. In my lab- 

 oratory we keep one or two jars with a layer of wet sand in the bottom; 

 into these relaxing jars dried insects can be put at any time, and made ready 

 for pinning. 



