38 ROUSSELET : DELICATE ORGANISMS. 



of preferably distilled water ; after the crystals are dissolved, 

 which may take a few hours, the solution is transferred into a 

 small, glass stoppered stock bottle. 



III. Formalin 7 per cent., (not formaldehyde 7 per 

 cent). For distant lands it is best to take a bottle of the 

 commercial formalin (40 per cent, formaldehyde) which can 

 be reduced with water as required. (Formalin 7 parts, water 

 93 parts, or say i to 13). 



APPARATUS REQUIRED. 



Plankton net, or stick with straining ring net, made of 

 bolting silk (or "soft mull" cotton material) with small 

 bottle attached. 



Flat bottle. 



Glass pipettes, straight, 6 to 7 inches long, provided with 

 India rubber teat. 



Bottles of various sizes. 



Small tube bottles for collected specimens. 



