PLATE 22 
i, 2.—Plant 5 of Ricinus communis * injected August 15, 1916, with 1 to 1,200 
ammonia water (aqua ammonia sp. gr. 0.90,1 part, distilled water 1,200 parts). Both 
faces of the upper part of the second injected intemode (main axis) show knobs and 
glistening strands of proliferated pith tissue. Below there was a continuous sheet of 
glistening proliferated cells. There were evidences of pith injury in the lower pat of 
the intemode but none in this part. Photographed on September n. X 3 . 
