IAE 
AMERICAN NATURALIST 
VoL. XXXIV. July, 1900. No. 403. 
NOTES ON A SPECIES OF PELOMYXA. 
H V. WILSON, 
IN rearing amcebas for class use, as every one knows, many 
interesting protozoa make their appearance. The Pelomyxa 
described in this communication developed in great numbers, 
something over a year ago, in a “culture” which had been pre- 
pared for this purpose. The method of preparation was one 
that I have employed for several years, and is as follows. Into 
an ordinary wooden tub (2 ft. by 1 ft.) sand is poured to a 
depth of four inches. The tub is then put under the tap of a 
table aquarium, and flushed until the water is comparatively 
clear. A good handful of Nitella, two or three opened mussels, 
and a crayfish, cut into a couple of pieces, are thrown into the 
water and partially imbedded in the sand. The tub is left 
exposed to a north light from large windows, at a distance of 
some yards from the windows. As decomposition progresses, 
a very gentle stream of water is turned on for a short time 
every few days. After an interval varying from two or three 
weeks to two months, large amcebas (A. proteus) are found in 
abundance in the surface layer of the sand, and on the sides of 
the tub. Small amcebas frequently appear in numbers before 
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