PLATE 4 
A.—Aspen (radial section) attached by PeniciUium .Note 
is to be sTen teTts cZse through a group of parenchyma cells. Stamed with dilute 
gold chlorid from 8 a. m. to 4 P- 
* C and D.—Aspen, same as A, but m tangential section. 
