Notes and Brief Articles 



95 



Many attempts were made to increase the virulence of biologic 

 forms on resistant hosts by successive transfers to these hosts. 

 The results indicated that rust forms do not gradually adapt 

 themselves to resistant or semicongenial hosts. 



Biologic forms seem to be roughly analogous to pure lines. . 

 Plus and minus fluctuations may occur, but there is always a 

 tendency to return to normal. 



The facts given in this paper do not support the conclusions of 

 previous workers that the pathogenicity of biologic forms is easily 

 changed by host influence. 



From the practical standpoint the constancy of biologic forms is 

 of great importance. Breeding for rust resistance can proceed 

 with considerable assurance that the same rust will not adapt itself 

 quickly to new varieties. 



George Francis Atkinson 



Professor Atkinson died in the City Hospital, Tacoma, Wash- 

 ington, on November 14, 191 8, from pneumonia following an 

 attack of Spanish influenza. He was recently relieved of active 

 work at Cornell University, where he had been Head of the De- 

 partment of Botany since 1896, to prepare his extensive notes and 

 photographs of the fleshy fungi for publication. In order to 

 make this work more complete, he was engaged in collecting fungi 

 in regions he had not previously visited, his last explorations 

 being on Mt. Rainier and about Tacoma. 



Professor Atkinson has served as a member of the Advisory 

 Board of North American Flora, published by the New York 

 Botanical Garden, since the begmning of that work in 1905 ; and 

 was an associate editor of the Botanical Gazette. His publica- 

 tions cover a wide range of subjects, including plant pathology, 

 morphology, taxonomy, embryology, heredity, life-history, etc. 

 He was the author of a number of botanical text-books and 

 numerous contributions to botanical journals, making a total of 

 over 125 titles. 



The enthusiasm and energy displayed by Professor Atkinson in 

 personal research and in directing the investigations of others has 

 scarcely been equaled. To his students in all parts of the country. 



