EXPLANATION OF THE PLATES. 



PLATE I. 



Upper and lower surfaces of a diseased castor leaf. 



PLATE II. 



Fig. 1. .Surface view of a castor leaf showing sporangiophores emerging through 



stomata and between the cell-walls of contiguous epidermal cells. — 



Somewhat diagrammatic. Drawn by Dr. E. J. Butler. X 320. 

 „ 2. Transverse section of the stem of a castor seedling showing the presence 



of hyphse in the vessels and in the bundle sheath. Drawn by Dr. 



E. J. Butler. X 320. 

 i} 3. Longitudinal section of a pitted vessel showing a hypha leaving through 



a pit, X 640. 

 „ 4. Transverse section of the woody portion of the pericarp of a fruit 



showing the hypha? boring through the lignificd cell-walls by means 



of fine projection tubes. X 640. 

 ■ , 5. Transverse section made at the collar of a castor seedling showing 



palmately branched hyphse in cells of the cortex. X 640. 

 ., 6. Transverse section of a stem of a castor seedling showing hyphse 



swelling into globular heads just underneath the epidermis before 



breaking through it. X 405. 

 „ 7. Transverse section of a stem of a castor seedling. A cluster of hypha! 



breaking through the epidermis. On the left is the swollen bead 



of a hypha just below the epidermis. X 405. 



PLATE 111. 



Fig. 1, A sporangium producing a highly branched vegetative mycelium when 



kept in the dark for twenty-four hours. (From a water culture.) 



X 100. 

 ,, 2. Transverse section of a stem of a castor seedling. A is an intracellular 



branch of an intercellular hypha. At B are finger-shaped haustoria. 



X 405. 

 ., 3. Button shaped haustoria. X 405. 



4. A branched haustorium. X 105. 



5. Transverse section of a castor leaf . Two germ-tubes entering i1 through 



a stoma. X 405. 



