Preparatio7i 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 dement, 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. 



Volvox, 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. 



