Journal of 



Applied Microscopy. 



Volume II. JUNE, 1899. Number 6 



Methods of Studying and Mounting Protozoa. 



Among the various manuals devoted to microscopical methods — collecting, 

 killing, staining, etc., few accessible to the amateur give any particular attention 

 to the technique of preparing the Protozoa for study, even in the living state, and 

 more particularly for making the permanent mounting of such for critical study 

 or preservation. Lee, in the Vaiie-Meawi, gives a few paragraphs on the subject, 

 and cites a few notes from a variety of sources, few of which are directly avail- 

 able to the beginner. 



In view of the interest, and importance as well, it has occurred to me that a 

 brief summary of methods, and some account of personal experience, might 

 prove helpful to readers of the Journal, and thus in a way contribute to con- 

 tinued interest in the microscope, both as a means of entertainment and as a 

 source of important information in the lines of applied microscopy, as well as to 

 teachers whose work lies along the lines indicated. A similar contribution 

 several years ago to the American Motithly Microscopical Journal, Vol. X, elicited 

 a number of inquiries which implied a wider interest in the general subject than 

 would at first thought seem likely. To mention only teachers of zoology, who 

 know all too well how uncertain is a supply of such organisms in the living state 

 for general class-work at a given time, and who would gladly welcome some 

 means by which even the less satisfactory mounted specimen could be readily 

 available in an emergency, is, I take it, sufficient warrant for the time and space 

 necessary for a statement of " how it may he done.'''' 



As preliminary, it may not be amiss to briefly consider methods for the critical 

 study of living specimens. In the case of Amoeba, or the more or less sedentary 

 Protozoa, little precaution in the way of supporting the cover-glass, or rendering 

 the specimens quiescent, is necessary. But for Paramcecium, Stylonichia, and 

 others of similar activity, some method of restricting their movements is a practi- 

 cal necessity. The use of certain narcotics, such as chloral hydrate, cocoaine, 

 nicotine, etc., I have not found satisfactory, as sooner or later its presence sets 

 up pathological conditions which materially vitiate the very ends sought in such 

 study. The same is somewhat true of the use of such gelatinous substances as 

 cherry-gum, etc., for checking their activities. In my own experience nothing 

 has proved more satisfactory than a few shreds of absorbent cotton, or a fine 

 alga, under the cover-glass, so tangled as to limit the movements within a narrow 



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