156 ILLINOIS ACADEMY OF SCIENCE 



(1909), who states that '' the sooty blotch and fly speck 

 are apparently stages of the same fungus" and pro- 

 visionally refers to them as one fungus, though the evi- 

 dence on which he bases his conclusions is not presented. 



Since the publication of Duggar's book (1909), 

 Leptotliyrhim Pomi (Mont, et Fr.) Sacc. has been quite 

 generally accepted as the technical name for the two 

 fungi, though this usage is not universal. In a recent 

 letter,*' Gr. R. Lyman of the U. S. Dept. of Agriculture, 

 Plant Disease Survey, states that most of their collabora- 

 tors refer to Leptothyrium Pomi (Mont, et Fr.) Sacc, as 

 the cause of sooty blotch, and a smaller number attribute 

 fly speck to this fungiis. Sheldon, Cook, and Clinton refer 

 to Phyllacliora pomigena (Schw.) Sacc, as the cause of 

 sooty blotch. 



The following herbarium specimens were examined. 

 The label on the packet is given as well as the herbarium 

 or set of exsiccati from which the specimen was received. 

 In the column headed ''sooty blotch" are placed the 

 names of the specimens classified by the writer as such : 

 in the column "fl^^ speck" are placed those classified by 

 him under that name. 



SOOTY BLOTCH 



Phyllacliora pomigena Schw. Sacc Pirus malus. Win- 

 chester, Va. Oct. 21, 1908. Com. M. B. Waite. Det. M. B. 

 Waite. From U. S. Dept. of Agr. 



Pliyllachora pomigena (Schw.) Sacc. From Giltner 

 in Hamilton Co. Collector Mrs. E. D. Snider, 22 Sept. 

 1909. Herbarium of Plant Pathology, Dept. of Agricul- 

 tural Botany. Univ. of Nebr. Plant Disease Survey. 

 From U. S. Dept. of Agr. 



FLY SPECK 



Disease of Malus malus ''Genitan". Caused by Lep- 

 tothyrium pomi. From Eed Cloud. Collector J. M. 

 Bates, Jan. 31, 1908. Herbarium of Plant Pathology, 

 Dept. of Agricultural Botany, Univ. of Nebr. Plant 

 Disease Survey. From U. S. Dept. of Agr. 



''Letter of March 10, 1919. 



