IIOJV TO COLLECT MOSQUITOES 223 



deln," which are sold by Queen & Co., Philadel^jhia, 

 and other hirg-e dealers in such thing's. These pins are 

 so small and delicate that they may be thrust through 

 the thorax of the mosquito and into a little strip of cork, 

 the cork strip itself being pinned upon one of the larger 

 and longer insect pins. 



Some collectors, instead of using the chloroform meth- 

 od of killing, prefer the cyanide bottle. The cyanide 

 bottle is made by taking a wide-mouthed tiask, putting 

 a small lump of cyanide of potassium at the bottom and 

 covering it with a layer of liquid plaster of Paris, which, 

 when allowed to set, makes a complete layer over and 

 around the cyanide and prevents the water that comes 

 from the deliquescence of the cyanide from injuring 

 specimens that are i^laced in the vial, but which at the 

 same time is sufficiently porous to permit the escape of 

 the deadly cyanide fumes. Even with the layer of plas- 

 ter of Paris, however, the cyanide bottle will sometimes 

 become wet, so that a bit of blotting-paper may with 

 advantage be inserted to cover the plaster of Paris, and 

 to absorb the superfluous moisture. A mosquito capt- 

 ured in one of these cyanide flasks or vials dies very 

 quickly and is in good condition for dry mounting or for 

 transfer to pill boxes. The cyanide bottle is preferably 

 stoppered with a cork stopper, but rubber stoppers are 

 also used. 



In collecting early stages of mosquitoes it is only nec- 

 essary to have a supply of bottles, a little coffee-strainer 

 with a handle, and a large reading-glass. Other appar- 

 atus is cumbersome and imnecessary. I have a large 



