300 BOTANICAL GAZETTE [ocToBER 
plant is fixed connects with the cylinder at 5 in fg.2. Drawn froma photo- 
graph. One-sixteenth natural size. 
Fig. 2. Section of compression pump. 1. Fitting around piston rod. 
The piston rod is driven by the lever handle to which it is connected above. 2. 
Stopcock leading into the open air; not closed when the pump is used for 
compression. 3. Piston head moving “air tight” in a metal cylinder. 4. 
falve. 5. Outflow pipe through which compressed air is forced. This pipe 
is extended horizontally in the opposite direction and upward to a point near 
the base of the crooked lead tube leading to the plant, in the apparatus shown 
in fig.z. Ata point near the juncture with the lead tube it is furnished with 
a stopcock leading into the open air, which is to be closed during the com- 
pression stroke and opened when the stroke is reversed. In Jig. 1 the cylinder 
is surrounded by a safety casing not shown in fig. 2._ One-eighth natural size. 
The plate for fig. 2 was copied from the original drawing of the apparatus, 
and was kindly furnished me by the designer, Mr. Eugene Albrecht, Uni- 
versitats- mechaniker, Tiibingen, and I am indebted to him for permission to 
reproduce it here. 
