since been questioned by Van Vloten (63), Ellis and Gill (15), 

 Boyce (5), and Weistaner (68). 



Wilson and Wilson (70) first reported the disease in Europe in 

 1926, and described its symptoms on two varieties of Douglas-fir in 

 Scotland. They traced the development of the fungus in the needles 

 and gave the first summary of the life history of the fungus. The 

 initial infection in Scotland was believed to have originated from 

 Douglas-fir transplant stock imported from the Northwestern United 

 States and Canada. Wind dissemination of ascospores was suggested 

 as the probable source of a second infection in an area eight miles 

 from the first. 



Boyce (2) in 1926 reported the epidemic nature of the fungus on 

 Douglas-fir in Scotland as contrasted to its endemic nature in its 

 native habitat. He observed the apparent immunity of the fast- 

 growing green strain of Douglas-fir. A year later, however, Boyce (3) 

 suggested the possibility of fungus adaptation to the green strain. 



In his summary of the biology of R. pseudotsugae, Day (13) 

 questioned the efficacy of spraying and recommended the use of 

 silvicultural controls. 



A review of the Rhabdocline disease situation in England by 

 Wilson (69) outlined chronologically the development of the fungus 

 on the needles and stated that death normally occurred after three 

 to five years, at which time the trees were completely defoliated. He 

 observed the continued apparent resistance of the green strain to the 

 fungus, but questioned its ability to remain immune. 



In the United States, Boyce (4) in 1928 found Rhabdocline 

 needle cast in Douglas-fir plantations for the first time in the North- 

 east (eastern Massachusetts). He theorized that the fungus was 

 introduced on nursery stock, from either the Pacific Northwest 

 or Europe. 



Brown (7) made a detailed study of the premature fall of Douglas- 

 fir needles infected with R. pseudotsugae. He concluded that lowered 

 water content in infected needles resulted in their early fall. 



In 1931, Liese (26) in Germany reported the occurrence of the 

 fungus on the green strain or Douglas-fir. He suggested the proba- 

 bility of long distance spore dispersal as a means of rapid spread of 

 the disease and, as a control measure, recommended cutting and 

 burning all infected branches before apothecial formation in the 

 spring. 



Liese (28) summarized the effects of Rhabdocline needle cast on 



