568 



SPECIAL PLANT PATHOLOGY 



Fig. 206. — CEdema on Manihot (Ceara). A, Normal arrangement of leaf tis- 

 sues; B, division and enlargement of palisade cells in oedematous leaf; C, division of 

 cells in the spongy parenchyma which become giant cells; D, early stages of disease 

 in which all of the cells except lower epidermal ones are oedematous; E, division and 

 enlargement of cells in lower epidermis; F, cedeinatous leaf tissue double that of 

 normal leaf; C, shrinking and collapse of cells in oedematous leaf. (After Wolf and 

 Lloyd, Phytopathology, 2: 134, pi. xi.) 



