Preparation and Mounting of Vegetable Tissues 181 



and make the sections with a Cathcart microtome, wash 

 away all trace of gum with repeated changes of warm water, 

 and mount unstained in glycerine jelly. 



Preserving Fluid for Green Algae. Acetate of copper 

 15 grains; camphor water, 8 ounces; glacial acetic acid, 

 20 drops ; glycerine, 8 ounces ; corrosive sublimate, 1 grain. 

 Mix well together, filter, and keep in a stoppered bottle. 

 The above fluid preserves the colour of chlorophyll for a 

 long time ; it may also be used as a mounting fluid. For 

 very delicate specimens leave out the glycerine. 



The specimens should be well washed in water ; then 

 pour off the water, and add a quantity of the copper 

 solution. 



To Mount in the Above. For example, take spirogyra, 

 as a filamentous alga. Make a cell with some black cement, 

 and let it dry; then apply a second coat of cement, and 

 allow this to nearly dry. Place some spirogyra in the cell, 

 and with needles separate the filaments ; add a few drops 

 of copper solution, and apply a cover-glass as directed for 

 yeast. 



Protococcus. This can be obtained by scraping the 

 bark of trees. Place it in a bottle of water, and let it stand 

 for a few hours ; now add a little copper solution this will 

 kill the specimens, and they will sink to the bottom of the 

 bottle ; pour off the water, and add more copper solution. 

 Now make a cell as for spirogyra ; take up some of the 

 protococcus in a dipping-tube, and place them in the cell ; 

 wait a minute for the forms to settle on the bottom of the 

 cell, and then apply a cover-glass ; drain off the excess 

 of fluid, dry the slides with a cloth, and apply a coat of 

 cement. 



Yolvox, gloeocapsa, desmids, etc., may all be preserved 

 and mounted as above. 



Antheridia and Archegonia of Mosses. Place some 

 male and female heads of mosses in methylated spirit for a 

 few days, then transfer to equal parts of absolute alcohol 

 and ether, in which they must be soaked for several hours. 



