145 



B. Phytophthora infestans. HYPHJE WITH 

 CONIDIA. X. 100. (Zeiss Apochromatic Ob- 

 jective and Projection Ocular.) The upper 

 portion of the hyphse only is shown. Fig. 23. 



F. Phytophthora infestans. MYCELIUM IN CELLS OF TUBER. 

 x. 200. (Zeiss Apochromatic Objective and Projection Ocular.) The 

 illustration shows two angles of one cell, the cell-walls being scarcely 

 traceable ; also probably the direction of another cell-wall overlying 

 the h'rst. The mycelium travels between the cell-walls, expanding 

 the intercellular spaces, and finally breaking them down. The cell 

 contents were previously dissolved out. Fig. 24. 



