COLLECTING, FIXING, &c. 9 



equisetum, &c. For flower or leaf buds take two parts of the solution 

 and add one part of water, and for more delicate objects still (spirogyra) 

 I take equal parts of the sohition and water (Fig. 2). 



^i'jfy^ 



Fig. 2, — Spirogyra, fixed with equal parts of the chromo-acetic solution and water, 

 magnified 80 dia. A, frond in normal vegetative condition; B, in conjugation. 



This solution, with careful modifications, some knowledge relating 

 to the nature of the objects under manipulation, and common sense, 

 will serve as a fixative for, practically, the whole range of vegetable 

 histology. After fixation the specimens must be treated as described 

 above. 



3. Corrosive-picro-formaldehyde Sohition. 



Boiling water, 100 cc, 1 • 1 



^ . 11-^ ^ Dissolve and add 



Corrosive sublimate, 2^5 grams, J 



Picric acid, i gram. 



Allow to cool, and immediately before use add 



Formaldehyde, 40 per cent. 10 cc. 



This solution fixes vegetable and animal cells and their contents, 

 perhaps, more completely than any known fixative. I have used it for 



