Journal of Applied Microscopy. 395 



cent, alcohol — this may require thirty seconds or several minutes ;* rinse in 70 

 per cent, alcohol until a bright red replaces the yellowish color due to the acid, 

 and then proceed as usual. 



Iodine Greeii. — A 1 per cent solution in 70 per cent alcohol is good for the 

 vascular system of plants. This stain resists the washing-out process better 

 than methyl green. Stain in iodine green at least an hour, and it is not a bad 

 plan to stain over night ; rinse in 70 per cent, alcohol ; stain 15 seconds to one 

 minute in erythrosin, and proceed as usual. Methyl green may be made and 

 used in the same way. 



Fuchsm and Iodine Green Mixtures. — Two solutions are kept separate, since 

 they do not retain their efficiency long after they are mixed. 



0.1 gr. fuchsin (acid). 

 50 cc. distilled water. 



{ 



-p ( 0.1 gr. iodine green. 

 ( 50 cc. distilled water. 



100 cc. absolute alcohol. 

 C -^ 1 cc. glacial acetic acid. 

 0.1 gr. iodine. 



Mix equal parts of A and B. Transfer to the stain from water. The proper 

 time must be determined by experiment. Transfer from the stain directly to 

 solution C and from C to xylol. 



Another formula : 



A. 0.5 gr. acid fuchsin. 



B. 0.5 gr. iodine green. 



Mix a pipette full of A with a pipette full of B ; stain two to eight minutes ; 

 transfer to 85 per cent, or 95 per cent, alcohol, dehydrate rapidly, clear in xylol, 

 and mount in balsam. Both these formulae are good for kar}^okinesis. 



Bistnark Brown. — Use a 2 per cent, solution in 70 per cent, alcohol. If 

 material has been stained in bulk in one of the carmines, a few minutes staining 

 on the slide with Bismark brown gives a good contrast. It is particularly good 

 for cell walls. 



Nigrosin. — Use a 1 or 2 per cent, solution in water. A few drops of this 

 solution to a watch glass full of water stains filamentous algae or fungi in one to 

 three hours. The stain keeps well in glycerine or balsam, but it is hard to get 

 these forms into balsam without more or less shrinking. 



( To be Continued.) 



If it is inconvenient to use a pipette for drawing oif the water from a watch- 

 glass containing small organisms, a couple of threads dipping over the side will 

 serve the purpose. 



Hydra, worms, and other animal forms that it is desired to kill fully distended 

 may be stupefied by gradually adding small amounts of rochelle salts to the 

 water containing them. The time required varies ; it sometimes takes two or 

 three days. The animals become relaxed and do not contract when treated 

 with the fixing agent. 



