ETHER. Oestergren (Zeit. Wiss., Mik., xix, 1903, p. 300) 

 recommends a saturated solution (7-8%) in either sea- 

 water or fresh water, used either concentrated or diluted 

 to approximately 1%. 



MAGNESIUM SULPHATE. Often used as a saturated solution into 

 which the animals are plunged. More satisfactory results 

 are obtained however if the crystals are added to the water 

 containing the animals, or if it is introduced gradually 

 over a period of some hours to the water in the form of 

 a 20-30% solution. It is recommended for many marine forms, 

 especially Actinae. 



MENTHOL. One of the most useful narcotizing agents for many 

 marine animals. It has been chiefly recommended for 

 Mollusca, anemones (Zoantharia) , sea cucumbers (Holothuroi- 

 dea) , and sea squirts (Tunicata) . Animals are placed in a 

 clean vessel containing clean seawater, and crystals are 

 sprinkled on the surface. 



ROUSSELET'S SOLUTION. A well known mixture widely used for 

 narcotizing Rotifers and Polyzoa by many workers apparently 

 with success. The original formula consisted of: 



2% solution hydrochlorate of Cocaine 3 parts 



Methylated spirit 1 part 

 Water 6 parts 



Stovaine provides a satisfactory substitute for Cocaine. 

 The mixture is added drop by drop to the water containing 

 the animals. 



STOVAINE (Amyl Chlorohydrin) . This is a most useful and power- 

 ful narcotizing agent for small invertebrates. It now has 

 largely replaced cocaine which is difficult to obtain. It 

 is usually used as a 1% solution in distilled water which 

 is gradually added, over a period of time to the water 

 containing the expanded animals. 



TOBACCO SMOKE. An effective narcotizing agent for many small 

 organisms, such as Hydra and Infusoria. It should be slowly 

 and carefully bubbled into water through a fine glass tube 

 lying on the bottom of the container. 



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