140 ILLINOIS ACADEMY OF SCIENCE 



Sooty blotch is strictly superficial. It does not pene- 

 trate even the cuticle of the host, and causes no mal- 

 formation or cellular injury. It cannot, therefore, in the 

 strict sense of the word, be termed a disease and will 

 not be so discussed at this time. 



II. THE FUNGUS 



Names. The sooty blotch and fly speck have been 

 known for many years under a variety of names. Some 

 authors have used but one common name to include both 

 forms, while others have used two. The common names 

 employed are the following: Fruit spot, ink spot, fly 

 speck, sooty fungus, sooty mold, sooty spot, sooty blotch, 

 cloud, while technically the fungi have been placed in the 

 genera Monilia, Dothidea, Labrella, Xyloma, Sphaeria, 

 Leptothyrium, and Phyllachora. 



Practically all the common names listed are quite de- 

 scriptive and on that account are suitable for common 

 usuage. The name, sooty blotch, however, seems definite, 

 and because of its general use, is here adopted as the 

 common name of the fungus. 



Much confusion has arisen through the lack of uni- 

 formity in names, common as well as scientific, by which 

 the fungus is kno^^^l. This has resulted in uncertainity 

 on the part of anyone working in this field, as to exactly 

 which fungus is meant by any one common or scientific 

 name. It has therefore been thought wise to include in 

 the bibliography all available references of importance, 

 bearing on either of these fungi. 



History. The vague and incomplete technical descrip- 

 tions which have been given of these two fungi make it 

 difficult for the student to be certain Avhich fungus is 

 meant. In early studies of the fungi, stress was quite 

 naturally laid on the taxonomic side. Since 1894, how- 

 ever, the investigations have taken a practical turn, with 

 only a few isolated examples of taxonomic or morpho- 

 logical studies. 



What is now known as sooty blotch is first noted and 

 briefly described in this country by Schweinitz (1832), 



