408 The American Naturalist. [April, 
A small rubber tube, a meter or so long is connected with a vessel of 
ice-water partly stopped at the other end so that a slow stream passes 
through it. This tube is wrapped around the paraffine block upon the 
microtome and cools it off so that thin sections can be cut. 
If in winter the paraffine is too hard, the same device with warm 
water may be resorted to. 
