1891.] MICROSCOPICAL JOUENAL. 57 



weight enough to hold it in position. Then alcohol 95 per cent, was 

 allowed to run between the glasses, followed by pure glycerine (carbo- 

 lated). When the eddying currents had all ceased, more glycerine was 

 added to float ofl" the cover. The plant was then transferred to a cell 

 bv means of a thin spatula (of horn), a glass let down, and '^ clipped," 

 and half an hour later washed freely and a ring of cement added. 



The cement was prepared as follows : l^leached lac was dissolved in 

 alcohol 95 per cent, and made quite thin, allowed to settle, and the clear 

 amber liquor decanted and then allowed to evaporate down to proper 

 consistence to flow freely. To each ounce of the thick solution three 

 or four minims of castor oil and one or two of oil of lavender were added 

 (this latter chiejiy for perfume). This cement I keep as one of my 

 standards and commend it after a use of nearly fifteen years. Of course 

 it can be colored " to suit the taste." The present specimen has been 

 mounted about two years. — L. Brewer IlalL 



Corn Smut. — This slide was prepared from spores of corn smut col- 

 lected tiie previous season, cultivated in a moist chamber as follows : 

 Take a piece of blotting-paper an inch square, cut a ^-inch hole in it, 

 wet with water and place on a piece of glass ; then take a |-inch cover- 

 glass, breathe gently on it, and dust a few of the spores on it, place it 

 over the opening in blotting-paper with spores on the under side ; cover 

 with a bell-glass to keep out dust. In a few days the spores will germi- 

 nate, and can be kept in a growing condition by noiw and then moisten- 

 ing the blotting-paper. Many interesting slides can be prepared from 

 the spores of various fungi in this simple way. — E. L. Cheesetnan. 



Mounting Copepoda. — Cements and varnishes should be applied in 

 several successive thin coats rather than in one thick one ; in this way 

 the varnish will not spread. These specimens should have been placed 

 in distilled water when yet alive, in order that they might become free 

 froni the dirt adhering to them and contained within the alimentary 

 canal. When clean they may be dropped alive in carbolic acid, which 

 will render them transparent, and as it does not destroy anv of the tis- 

 sues we can study not only the outer covering but the internal organs as 

 well. Insects dropped alive into carbolic acid become nicely extended 

 before they die. To mount, remove excess of acid and cover with chlo- 

 roform balsam. This method is suitable for all small insects that are 

 not too dark. — H. M. Lyon. 



The Potash Method is good enough for large opaque bugs ; but 

 for pediculi and such small and transparent insects the following is bet- 

 ter : Take a slide with a shallow varnish or other cell, place a drop of 

 Tarrant's solution (gum and glycerine) in the centre, drop the living 

 vermin in the fluid. It will struggle and straighten itself out and die, 

 and soon become transparent enough to show up all its important inter- 

 nal organs, muscles, and tracheae. A ring of cement to seal the cover 

 down finishes the slide. One then has a mount of a whole insect, worth 

 study ; not simply an empty skin flattened out of shape. — 6". G. Shanks. 



Better kill and render transparent in carbolic acid, and mount in bal- 

 sam. This has at least been my experience. — //. M. L. 



Carbolic Acid Mounting. — The fly was decapitated after immer- 

 sion for a few minutes in carbolic acid (pure crystals liquefied by heat). 

 The separated head was covered by a drop of balsam in turpentine and 

 alcohol and- a cover applied, completing the mount in from three to 



