THE Microscope. 299 
Those Infusoria and Rotifers which attach themselves singly 
or in social groups to the rootlets and leaves of aquatic plants, 
must be examined while in the position they have selected. To 
do this the leaf of Myriophyllum oc a rootlet of Lemna is cut 
off, and gently transferred to the slide, with a little water. 
Carefully go over every part, especially the angles and the 
secluded corners, for it is there that the little creatures love to 
conceal themselves. It is usually well to look for them with a 
low power objective, if the glass is a good one, and the observy- 
er’s eye is trained to the work. 
To transfer the free swimming forms to the slide a dipping tube 
is necessary. This useful appliance is described in elementary 
books on the use of the microscope, and known to the reader. 
And here again faith comes into play. The tube may at the 
first attempt be full of curious creatures, or it may have picked 
up nothing but dirt. The result can be known only when the 
drop is examined under the microscope. But to make and keep 
the microscopical aquarium is entirely within every one’s control. 
NOTES ON THE MICROSCOPE STAND, AND SOME OF 
ITS ACCESSORIES. 
AN AMATEUR, 
Il. 
THE BODY-TUBE (CONTINUED). 
ANY stands of this kind have the short body lined with 
cloth, an arrangement that for a time insures a smooth 
and easy movement of the draw tube. Soon, however, especially 
if much used, the latter will begin to move less smoothly, until 
finally it will demand considerable muscular effort and both 
hands. The difficulty is caused by the roughening of the cloth 
lining, which must be remedied before the tube can again be 
moved easily. To do this, take out the draw tube and heat it 
until it is so hot that it cannot be held without some discomfort, 
and gently force it into the body where it must remain until 
cold. This in effect irons the lning, which the experimentor 
must be careful not to burn. If one ironing is not sufficient the 
heating may be repeated. 
At the present day the objectives of any optician may be used 
on the stand of any maker, yet this convenient arrangement is 
only a comparatively few years old. Before the screw on the 
