— log— 



selecting those least broken up.) From a lot thus separated I 

 select several for examination entire, removing them to another 

 clean glass slip into a drop or two of clean water, or dilute glycer- 

 ine, and covering them with a cover glass. They are now ready 

 for the compound microscope, and may be temporarily laid aside 

 till all the other slips are prepared. 



The preparation of cross sections of the leaves is a somewhat 

 more delicate task. I again select three or four of the best leaves, 

 and transfer them to another slip into a little water. Under the 

 dissecting lens I now endeavor to hold them with bent needle 

 down into the water on the slip, bases toward me and to the left, 

 apex away from me and toward right. This with the left hand. 

 Then I cut with a chop- knife motion across the leaves, endeavor- 

 ing to cut very thin, parallel slices. The scalpel of course must be 

 kept very sharp, and I always keep a fine hone and razor strop on 

 my work table. The difficulty of this operation, which is viewed 

 through the lens, is fast diminished by practice. It arises from 

 the surface tension of the water, which is somewhat violently 

 disturbed by the touch of the scalpel, on the edge of which a 

 meniscus leaps up to a microscopically considerable height, caus- 

 ing the small moss pieces to dance a lively jig for a moment, and 

 throwing them into confusion. With this disturbance one soon 

 learns to reckon in this process of working. The thinnest sections 

 are soon selected, and are lifted with needle and scalpel on to 

 another slip into a drop of water or glycerine, and covered with a 

 circle. 



The capsule I cut crosswise first, close to the peristome. If 

 spores are too abundant, and are likely to interfere with the exam ■ 

 ination, I endeavor to press and work out the bulk of them, trans- 

 ferring the washed parts to another slip with a drop of water. 

 Then I split each part again lengthwise ; the base of the capsule 

 thus split is carefully laid with outer surface turned upward ; the 

 peristome pieces are arranged so that one has the outer, the other 

 the inner surface turned upward, for obvious reasons The parts 

 are then covered with a cover glass, and everything is ready for a 

 detailed microscopic examination. 



Finally, if it is found necessary to determine the presence of 

 the gametophyte on the plant, as perfect a plant as possible is 

 selected after soaking, and is carefully looked over with the dis- 

 secting lens for small buds of somewhat different construction 

 than ordinary short stems. These buds are then split lengthwise 

 in a drop of water, the parts floated out, and covered. 



