FUNDAMENTAL CONSIDERATIONS 
9 
2. Staining . — For two reasons it is generally better to stain plant 
tissues before mounting. Transparent tissues may become almost 
invisible in glycerine or balsam, and different tissues take a stain 
differently. This being the case it becomes possible to stain one 
tissue and not another, or one tissue with one stain and another in 
the same seel ion with a different stain, so that the different parts 
may be brought out like areas on a colored map. The most common 
stains are hsematoxylin derived from logwood, and various anilin 
stains — safranin, fuchsin, eosin, iodine green, methyl-green, etc. 
METHOD FOR THE PREPARATION OF A CANADA BALSAM MOUNT 
1. Stain object with 0.5 per cent, solution of safranin in 50 per 
cent, alcohol for from three to five minutes. 
2. Wash out excess of stain and further dehydrate with 70 per 
cent, alcohol. 
3. Stain with 0.5 per cent, solution of methyl-green in 70 per cent, 
alcohol for twenty seconds or longer, depending upon the nature of 
the material. 
4. Dehydrate and wash out excess of stain with 95 per cent, alcohol 
for two minutes. 
5. Further dehydrate by placing material in absolute alcohol for 
one minute. 
6. Clear in cedar oil. 
7. Mount in Canada balsam. 
8. Label slide. 
METHOD FOR THE STAINING AND MOUNTING OF MATERIAL 
IN PARAFFINE RIBBONS AFFIXED TO SLIDE 
1. Gently heat the dry slides with paraffine ribbons adhering to 
the fixative, high above the Bunsen flame (with the ribbon side up). 
2. Place the slide upright in a well of xylol or turpentine. The 
xylol or turpentine will dissolve the melted paraffine in a minute 
or two. 
3. Take the slide out of the well, wipe off the under side and allow 
a stream of 95 per cent, alcohol to run over the upper side from a 
pipette. 
