24 
METHODS IN PLANT HISTOLOGY 
wash all day. For fern prothallia, onion roob-tips, lily anthers, and 
any material from such a size up to cubes a centimeter square, let the 
material wash for 24 hours. Even for delicate algae, 24 hours does 
no damage, and some of the best cytologists prefer the prolonged 
washing. 
Many methods have been devised for insuring thorough washing 
and for facilitating the process. The most obvious method is to 
allow a gentle stream of water to flow into the Stender dish or bottle 
containing the material. There is little danger in this method if the 
material is heavy enough to remain at the bottom: the only objection 
is that much of the water never reaches the bottom where it is needed. 
If material is lighter, tie a piece of cheese-cloth over the mouth of the 
bottle. 
A method devised by Dr. Dudgeon is simple and very efficient, 
especially for delicate material or objects which have a tendency to 
float. A glass tube, 1 inch in diameter, is cut into pieces 2f inches 
in length. The glass is then heated to round off the sharp edges and, 
while the glass is still very hot, one end is flared a little, so that a 
piece of cloth can be tied over or fastened over it with a rubber band. 
Bolting cloth or bolting silk is best because water passes through it 
so readily. A number of these tubes can be placed in a dish not quite 
so deep as the tubes and water can flow into the dish without any 
danger of making the tubes overflow. With material which does not 
settle readily, this method is a great time-saver. 
An apparatus for washing several collections at one time may be 
made as follows: Get a piece of f-inch lead pipe, bore holes about 
or f inch in diameter and about 1| inches apart, put a short rubber 
tube in each hole and the glass part of a pipette in the end of each 
rubber tube. Connect the lead tube with the faucet by a large 
rubber tube. A still better way is to bore T \-inch holes in the lead 
tube, screw into these holes short brass tubes, and then fasten the 
pipettes to the brass tubes with thin rubber tubes. 
If there are no facilities for working with metal, take a wooden 
box about 6 inches wide, 18 inches long, and 4 inches deep; bore 
f-inch holes in the bottom, and into each hole put a piece of rubber 
tubing about 4 or 5 inches in length. The pipettes can be fastened 
in the ends of these rubber tubes. Place the box under the tap. In 
the botanical laboratory at Woods Hole, Massachusetts, large 
quantities of material are washed at one time by using an ordinary 
