ole THe MICROSCOPE. 
iant, kind——dead. He prefered such a stage, because the milled. 
heads did not then occupy any space on the surface, their absence 
leaving more room for larger slides. But to carry a slide exceed- 
ing the standard size of three inches by one, the whole stage 
must be modified, or the slide must be manipulated directly by 
the fingers, when many of the advantages of the mechanical ac- 
cessory would be lost. A movement of an inch in each direc- 
tion is ample. Mr Zentmayer’s mechanical stage is superb in 
workmanship, admirable in the aadition of graduations and other 
facilities, but it is objectionable, I think, on account of the later- 
ally projecting milled heads, although they accomplish a hori- 
zontal motion of one and one-fourth inches, and a vertical move- 
ment of one and one-eighth inches, the stage being five inches 
in diameter. Those who are pleased with such an arrangement 
of the working parts, will find this the best stage made in this 
country, which means the best in the world. It costs forty dol- 
lars, and is prepared for the American Centennial stand; either 
reason probably being sufficient to preclude its attainment by 
the beginner. 
A USEFUL COLLECTING DEVICE. 
JOHN WALKER. 
\ HILE pursuing my investigations among the ciliate and 
flagellate Infusoria, Diatomacez and Rotifera that abound 
in the ponds and lakes around Minneapolis and vicinity, I 
came to the conclusion that a collecting bottle less cumbersome 
than the usual affair would be desirable. The one that I had 
been using, a modification of the Wright pattern, has some ad- 
vantages over the original, yet it is open to objections. In the 
first place, it is too large to be conveniently carried about when 
one is off for a ramble through the woods in search of those 
secluded clear-water pools, wherein abound the finer forms of 
microscopic plants which the student of the Desmidieze knows 
so well. Secondly, the strainer, though an improvement over 
the Wright form, is still rather disappointing, as it must be taken 
out frequently to be cleaned. 
Such being my experience, I decided to use a smaller bottle, 
and have the strainer (I use bolting silk, 1U,CGO to the inch), 
outside instead of inside. I therefore procured a bottle holding 
about four ounces. A square bottle with a wide mouth is pref- 
