6 THE CELLS OF MOSSES. 



noticed amongst the cells of these lowly plants, and a vast field of 

 study lies open before the diligent student. I shall add just one 

 other fact. Among the contents of the cells of some Mosses 

 have been found by several observers minute granules of starch 

 lying embedded in the grains of chlorophyll, and also globules of 

 oil. 



The preparation of specimens of the cells of mosses for exa- 

 mination under the microscope is indispensable. With fresh and 

 growing plants pure water is all that is required ; but for preserva- 

 tion in the cabinet some good niediiun in which the specimen will 

 be kept unaltered for years is to be desired. All those that have 

 yet been used have serious drawbacks. Canada balsam and 

 dammar make the moss-cell too clear and transparent. Anything 

 in which there is glycerine effects too much^ alteration in the 

 contents and walls of the cells ; while fluid mediums are, as we all 

 know to our grief, most unreliable. Here, then, is an [additional 

 reason for me to recommend the study of the cells of Mosses to 

 our members. A perfectly satisfactory and trustworthy medium 

 for mounting Mosses as microscopic objects, so as to have their 

 cells as they were when the plant was growing, is wanted. 



Saposchnikoff finds that sugar-cane can be transformed by 

 the leaves into starch. In his experiments he placed plants of 

 various sorts in the dark for a time ; then cut off some leaves and 

 bisected each along the midrib. One half was tested for starch ; 

 the other was laid for from four to eighteen days in a lo to 20 

 per cent, solution of cane-sugar, and then tested for starch both 

 with iodine and by Faulenbach's method. Starch was found in 

 abundance, especially along the veins. When the lower end of a 

 leaf of Cordylhie riibra was dipped 5 mm. in the sugar, the leaf 

 was black under the iodine test as far as 7 mm., from which point 

 up to 10 mm. the colour gradually became less deep, but extended 

 far along the veins. In variegated leaves only the chlorophyllous 

 cells formed starch. 



