76- THE MICROSCOPE. May 



PRACTICAL SUGGESTIONS. 



By L. a. WILLSON, 



CLE;VEI.AND, OHIO. 



Volvox globator. — This interesting" object can now be 

 found in man\' fresh-water ponds. When collected in a 

 g-lass jar or bottle, it may be easily seen with the unas- 

 sisted eye. They may be observed as little balls floating- 

 around in the water. They should be examined in a slide 

 with a hollow cell; a very shallow cell is preferable, for in 

 them the specimen may be examined with a one quarter 

 or on fifth objective. 



Glycerine Gelly for Mounting. — Many objects, especi- 

 ally objects containing- moisture, are unsuitable for mount- 

 ing- in balsam. For such objects, as for instance mosses, 

 liver mosses, stained leaf sections, spores and many others, 

 are best mounted in g-lycerine jelly. The jelly can more 

 conveniently be procured froin a dealer. 



Kaiser's Glycerine Jelly is composed as follows: — 



Finest French g-elatine, 1 part by weig-ht; soak two hours 

 in six parts by weight of distilled water. To this add 

 seven parts of chemically pure g-lycerine and to each one 

 hundred g-rams add one g-ram of carbolic acid; then warm 

 and stir constantly for ten or fifteen minutes until all flakes 

 disappear. Filter while still warm through funnel filled 

 with glass wool. Before using the wool wash it and place 

 in the funnel while still moist. The jelly should be 

 warmed each time it is used. When using-, warm the slide, 

 place a drop on it with a g-lass rod and warm the cover 

 g-lass before using. After cooling-, ring- the edg-e of the 

 cover with varnish or cement. 



Fixing the Cilia of Infusoria. — Use one part of tannic 

 acid to four parts of g-lycerine. On placing- a drop of 

 water containing the cilicita on the slide drop a minute 

 quantity of this fluid into the water and allow the two 

 fluids to flow together. If the right quantity of the fluids 

 is used the cilia will g-radually become more and more 

 distinct and will stand out plainly until the animal seems 

 to be entirely surrounded by them. 



