PAPERS ON BOTANY 



175 



EXPLANATION OF PLATES 



All plates are from photo-micrographs. The magnification used 

 in Plates 1-4 is indicated in connection with the figures. The draw- 

 ings for Plate 5 were made with the aid of a Bausch and Lomb drawing 

 apparatus and a Leitz number six objective, giving a magnification 

 of approximately 1,100 diameters, and are reduced' two-thirds. 



PLATE I 



Sooty blotch thalli of Fern-like type, x 160. 



Branching mycelium of one of the above thalli, x 300. 



PLATE n 



Immature pycnidia and mycelium, x 230. 

 Mature pycnidia and mycelium, x 230. 

 Sooty blotch thalli of the honey comb type, x 150. 

 Sooty blotch thalli of the reticulate type, x 230. 



PLATE m 



Cross section of sooty blotch pycnidium on apple, x 200. 

 Cross section of sooty blotch mycelium on pear, x 160. 

 Cross section of sooty blotch mycelium on apple, x 160. 

 Cross section of fly speck on watermelon, x 160. 

 Cross section of fly speck on apple, x 200. 



PLATE IV 



Antagonism of sooty blotch and fly speck on apple, x 2. 



Sooty blotch and fly speck on blackberry, x 2. 



Sooty blotch and fly speck on black mustard, x 2. 



Sooty blotch pycnidium forced open, x 200. 



Sooty blotch pycnidium with jagged aperture, x 230. 



Spores and paraphyses of sooty blotch, x 230. 



PLATE V 



Well developed thallus of sooty blotch. 



Younger stage of sooty blotch thallus. 



Still younger stage of sooty blotch thallus. 



A beginning stage in pycnidial formation; on apple bark. 



Later stage in pycnidial formation; on apple skin. 



Later stage in pycnidial formation. 



Nearly mature pycnidium. 



Conidia of sooty blotch. 



Paraphyses of sooty blotch. 



Cross section of sooty blotch mycelium. 



Diagram of cross section of sooty blotch pycnidium. 



