42 AMERICAN FERN JOURNAL 
to each other at the Brooklyn Botanic Garden and had 
the same amount of light and warmth. 
Note, however, the remarkable difference in size and 
general vigor. The plant shown at the right has pro- 
duced seven or eight fair sized leaves and a few of the 
slender rhizomes or stolons by which Nephrolepis spreads 
and propagates itself vegetatively. On the other hand, 
the plant at the left and above has between thirty and 
forty much larger leaves and a large number of vigor- 
ous branching stolons. 
In connection with these stolons is a large mass of 
roots with a few leaves showing. Herein lies the differ- 
ence in the size and growth of the two original plants. 
Both started out the same size, but the one on the left 
happened to send out one or more stolons so that these 
projected into a tank of water underneath. These 
straightway gave rise to roots and through them an 
increased amount of water and dissolved mineral matter 
was sent up and back to the parent plant in the pot. 
More food meant more leaves, and with each new leaf, 
a new stolon sent out to find the rich source of food be- 
low. 
The progression is geometric at least. The other 
plant whose root development was confined to the limits 
of the three inch pot could receive only the amount of 
water obtainable from the small quantity of soil in the 
pot. It would not do to stand such a pot in water, 
for then the roots would not obtain sufficient air, the 
soil would become heavy and ferment with the organic 
matter in it, and the plant would die rather quickly. 
But with the other plant, the pot and soil give it its 
mechanical support, the numerous stolons together with 
the leaves serve as breathing organs, and the mass of 
roots formed in the water absorb as much food as the 
leaves are able to utilize. An interesting fact in con- 
nection with the root system of Nephrolepis may be 
