124 • THE AMERICAN MONTHLY [Apr. 



marked differentiation of the tissue results. The cells of Perk- 

 inje can be beautifully traced to the very termination of their 

 branches, and a complete and striking network of nerve fibres 

 is seen, which will not tire the eye to study. — F. A. Rogers. 



Mounting Cyclops quadricornis. — Place them alive in 

 water in a proper ring and put on a cover glass. Then have 

 ready a mixture of equal parts of lime-water and glycerine. Soak 

 out the native water at one end with blotting paper and let the 

 lime-glycerine water run in at the other end until the cell is full 

 of the mixture. Then cautiously build up an outer ring, putting 

 a little and setting away to dry, then another and another. The 

 Cyclops is composed of carbonate of lime, and glycerine will en- 

 tirely destroy it ; but lime water added will counteract this des- 

 tructive effect. A proper cell is of white zinc, old and hard, a 

 year old preferred. This method will show the egg sacs and the 

 four horns (quadricornis) naturally in situ, and the red eye in all 

 its original splendor; and the mount will be a beauty and a joy 

 forever. These mounts may keep perfectly for ten years or even 

 longer. 



These animals may be stained in picrocarmine, and by careful 

 treatment mounted in glycerine or dammar, which shows the 

 internal structure also. — P. M. Club. 



MICROSCOPICAL APPARATUS. 



Second Hand Instruments. — Mr. Clarkson, Bartlett's 

 Buildings, Holborn, London, deals in all kinds of used optical 

 instruments. 



In reference to a railroad microscope stage adjustment 



as recently brought forth in England (Microscope Dec. 1894, 

 p. 180.) it may be said that I own a B stand of Tolles made 

 about 1874 in which the stage is moved by friction rollers 

 — that in 1890 said stage was exhibited to Hartnach at Berlin 

 and in 1887 in London to Mr. Lealand of Powell and Lealand 

 —It is American. N. Y. 1895, Jan. 31— E. Cutter. 



At the College of Physicians and Surgeons, Boston, there 

 were shown some fine micro-photos of diseased blood taken in 

 London with lime light eye-piece and objective by Dr. Keight- 

 ley of London. 



