224 Animal Micrology 



An ovary should be removed entire, stained with borax-car- 

 mine, dehydrated, cleared, and mounted in balsam. 



A testis should be treated in the same way as an ovary. Tease 

 it in the balsam before adding the cover-glass. 



To Keep Earthworms Alive in Winter, Jennings (Journal of 

 Applied Microscopy, Vol. VI, p. 2412) places them, immediately 

 after collection, into bacteria dishes (9 in. in diameter by 3 in. 

 deep) between folds of muslin which is kept damp but not drip- 

 ping wet. Not more than a dozen worms should be placed in one 

 dish and the cloth should be changed or washed at least every 

 two weeks. The worms may be fed on leaves, etc., from time to 

 time. 



To Immobilize Earthworms for study of circulation of the blood 

 under the microscope or projection lantern, Cole (Journal of 

 Applied Microscopy, Vol. VI, p. 2125) places them in a 0.2 

 per cent, aqueous solution of chloretone for 3 or 4 minutes. Such 

 worms may be slightly compressed between two slides. 



To Examine Corpuscles of the Coelomic Fluid, expose the worms 

 for a minute or two, to the vapor of chloroform. The coelomic 

 fluid exudes through dorsal pores. Touch a cover-glass to the 

 fluid and mount. 



The Setae Can Be Isolated by boiling a bit of the tissue con- 

 taining them in a solution of caustic potash. When isolated, dry 

 them and mount in balsam. 



LEECH 



Leeches are obtained from fresh-water pools, streams and 

 marshes, but to get sufficient numbers for class use it is usually 

 necessary to purchase them from dealers. Live leeches intended 

 for dissection may be killed with chloroform. Cross-sections 

 prepared in the same way as for earthworms are very instructive. 



ARTHROPODS 



For Mounting Small Crustacea see chap, xiii, iii, A. 



To Quiet Small Crustacea for Microscopical Examination ( Cole : 

 Journal of Applied Microscopy, Vol. VI, p. 2180) place them 

 in a watch-glass containing 2 parts of 1 per cent, chloretone and 



