lo MISCROSCOPICAL RESEARCH 



the fixation of developing pine buds, but have discarded it in favour of 

 the chromo-acetic solution. It fixes everything so completely that the 

 resinous substances in the cells, even after cutting the sections 

 extremely thin, is so dark that the albuminous contents can scarcely be 

 determined. After fixing, the specimens must be thoroughly washed, 

 and afterwards graduated to 92 per cent, alcohol, in which they may 

 remain for future use. 



4. Corrosive Stiblimate. 



(A) A saturated solution in water. 



(B) A saturated solution in 75 per cent, alcohol. 



The water solution is used chiefly for the fixation of delicate 

 specimens of the lower cryptogams. For use take 100 cc. of the 

 solution and to this add i cc. glacial acetic acid. Specimens will fix in 

 this solution in ten to fifteen minutes. After fixing, the specimens 

 should be washed in several changes of water, and then graduated to 

 92 per cent, alcohol, when the nature of the specimen will allow this to 

 be done without contraction of the tissue, in which case the specimens 

 should be placed direct into a solution made up of eight parts distilled 

 water and one part each of 92 per cent, alcohol and pure glycerine. 

 This solution will serve also for permanently mounting the specimen. 



When the alcoholic solution is used, which is applicable for general 

 purposes, the specimens must be washed in several changes of 75 per 

 cent, alcohol, to which a few drops of iodine solution, commercial, 

 should be added, so as to liberate any corrosive that may have 

 crystallised in the tissue, which if not removed may completely spoil 

 the finished preparation by the appearance of metallic masses. 

 When the iodine solution is added the alcohol takes on a brownish 

 colour, which, however, soon clears, and if the addition of the iodine be 



