Symbiotic Saprophytism \ 
BY 
DANIEL TREMBLY MACDOUGAL. 
University of Minnesota. 
With Plates I and II, and one Figure in the Text. 
HE extension of experimental evidence that plants of 
X the most diverse physiological constitution may use 
organic compounds as food, seems to point to the conclusion 
that all plants may take up and use more or less material 
of high molecular complexity. The green plant is essentially 
an organism adapted to the manufacture of its food from 
simple compounds by the aid of radiant energy. Any 
variation from this type of nutrition, by which the energy 
stored up in complex food-substances may become available, 
entails a corresponding modification of the entire metabolism 
of the organism, and is accompanied or followed by anato- 
mical changes. The extent of such alteration will roughly 
correspond with the proportionate amount of complex food 
used, and will be most apparent in the absorbing organs, 
chlorophyll-apparatus, and transpiratory surfaces. It is 
1 An abstract of this paper was read before the Botanical Society of America, 
Boston, August 20, 1898. 
[Annals of Botany, Vol. XIII. No. XLIX. March, 1899.] 
B 
