Ox Plant Pathology and Bacteriology 99 



ciated Rocstclia occuiiini; in this country.''* Professor Spalding 

 has evaluated as of that time the value of Farlow's work on the 

 black knot of plum and the gymnosporangium or cedar apples. 

 He said: 



Besides numerous otiicr papers by Dr. W". G. Farlow '® . . . that on 

 the Black knot of the plum and cherry is one of the most complete and 

 satisfactory. In this, for the first time, the complete history of the nature 

 and development of this disease and the means of checkint^ it were fully 

 discussed. Still more important from a scientific as well as practical stand- 

 point, are his later researches on the orchard rusts that in some portions 

 of the country have proven highly destructive to apple trees. The fungi 

 producing these rusts are now known to infest cedar trees during a portion 

 of their cycle of development and to pass from these to apple trees ; and 

 it has also been shown that certain varieties, notably wild crab apples, are 

 much more liable to infection than other kinds. From these facts, which 

 it has taken the labor of many years to establish, the following preventive 

 measures are indicated: 1. The cutting out of red cedars where they have 

 been allowed to grow in the vicinity of apple orchards. 2. The destruction 

 of wild crab apple trees that harbor the disease. 3. The selection of varie- 

 ties for cultivation that are least susceptible to its attacks. 



Thomas Jonathan Burrill, whom Gray recognized as early as 

 1872 as a cryptogamic botanist of extraordinary erudition, thanked 

 Farlow in 1881 for his recently published " Gymnosporangia or 

 cedar apples of the United States." He praised the work, saying: 



Your resume of the literature is of much interest and value while the 

 critical examination and comparison of species is, to my mind, the best 

 work of the kind so far produced in America. Not less interesting though 

 less conclusive is the account of your culture experiments. I sincerely 

 hope these may be repeated by yourself and others stimulated by your 

 example. 



BurriU ^' had been born in 1839 at Pittsfield, Massachusetts, 

 and when a youth nine years of age had migrated with his 

 family to a farm in Stephenson County, Illinois. During the sum- 

 mers he learned farming and during the winters attended a 

 country school. At an older age than usual he entered high school 



'■^W. a. Kellerman, journal of Mycology 9 (4th quar.): 244, Dec. 1903. 



** Prepared sometime between 1888 and 1890. Quotations taken from the origi- 

 nal manuscript found among the papers of Dr. Smith. 



''' Charles F. Hottes, Personal recollections of Thomas J. Burrill and his work, 

 Illinois Alumni News, 6-7, Feb. 1940; J. T. Barrett, Thomas Jonathan Burrill, 

 Phytopathology 8 (1): iff., Jan. 1918; also unpublished manuscript material by 

 Dean Eugene Davenport concerning Burrill. 



