7 
method of culture should be adopted which would retard the de- 
velopment of the mechanical tissue, and this is secured by growth 
in darkness. An increased proportion of that forced in winter will 
probably be cultivated in this manner. 
Fic. 1. Showing large leaf blades of rhubarb formed im light, and small ones in 
darkness. from block loaned by R. I. Experiment Station. 
The botanical interest in Professor Card’s experiments centers 
au 
ton on the relations of temperature and red colors. (See p. 11.) 
MYCORHIZAS OF ORCHIDS. 
The roots and underground organs of more than seven hun- 
dred species of orchids have been examined, and all of this num- 
ber are found to have formed unions with fungi in such a manner 
