420 The American Naturalist. [May, 
Without doubt these genera constitute a group entirely 
unique. They furnish great natural bacteriological laborato- 
ries in which the cultivation of microbes which are beneficial 
to the plant is carried on. It isin a certain sense a symbiosis 
between the lowest and the most highly organized plants. 
The higher organisms furnish a food supply for the use of the 
microbes in order that they may in turn be benefited by food 
stuffs which the lower organisms manufacture and furnish in 
convenient form. That the nitrogenous compounds set free 
by the dissolution of the egg albumen are really absorbed is 
shown by Darwin in his experiments. 
On the ground of his experiments the author offers his con- 
clusions as follows: 
Ist. The disintegration of albuminous compounds by the 
secretions of carnivorous plants is due to the growth of micro- 
organisms, principally bacteria. 
2. Micro-organisms possessing the power of dissolving 
albuminous compounds always vegetate in the secretions of 
completely developed carnivorous plants. 
3. The disintegration of the albumen does not commence 
at the moment of the secretion of the fluid, but only after 
micro-organisms have developed in sufficient numbers in the 
secretion. 
4. The micro-organisms found on the leaves of carnivorous 
plants come principally from the air, though they may be 
derived from other sources. 
The name “ carnivorous” plants is to be understood in 
the sense that the plants only assimilate the products which 
the lower organisms have set free. 
6. The rôle of the plant itself is only to furnish a medium 
in which certain micro-organisms may live and develop. 
