Chap. I.] BY THE SURFACE OF THE ROOTS. 
27 
the side-roots are taken off or left on, and whether 
the end of the main root is left in the water or 
out of it; or whether the end of the main root 
is cut off or left on the plant, or if the lower half 
of the radish is cut off, or if it is cut off within 
half an inch of the neck. When radishes have 
once been well saturated with water, they will 
remain alive for a long time under any circum¬ 
stances. 
If a radish is placed in a narrow-necked bottle, 
such as an eau de Cologne bottle, the absorption 
of water is very apparent by the decrease of water 
in the neck of the bottle. If the bottle is kept 
filled, so as to give all the radish the power of 
absorbing laterally, the radish will live. If the 
bottle is not kept filled, the radish will fade as 
the level of the water sinks to the immature parts 
of the radish. 
On the 13th of April, 1850, I instituted three 
experiments similar to these; but in earth in¬ 
stead of water. The results were equally favour¬ 
able to the position that the absorption of nutri¬ 
ment by roots is through the medium of their 
mature parts, and not through the medium of 
their immature ends. 
No. 1. From a ridge-bed, covered with matting 
at night, in which early potatoes and radishes 
