96 



FUNGOID DISEASES 



is not known, but probably via the root hairs. Once 

 inside, food is absorbed from the cell contents, ir- 

 ritation is set up, and the abnormal cells result in 



\1 



Fig, 27. — Finger-and-Toe Disease (Plasmodiophora brassicce). Showing 

 giant cells in portions of tissue taken from the abnormal growths on 

 roots ; note that the protoplasm of the fungus has broken up into a 

 mass of spores ; (a) spores more highly magnified ; (b) " germina- 

 tion " of spores ; (c) the ciliated portion of naked protoplasm emerging ; 

 (d) the naked protoplasm (plasmodium) liberated. (After Woronin.) 



consequence. Portions of protoplasm are capable 

 of piercing the cell wall and entering previously 

 healthy cells. 



How long the spores retain their power of ger- 

 mination, how winter is passed, and how the small 



