374 CONNECTICUT EXPERIMENT STATION REPORT, IQI2. 



apparently has spread outward with the development of seem- 

 ingly new infections. This apparent wave of progress, however, 

 is in part due to a corresponding wave of interest on the part 

 of the people to locate a disease so generally discussed. It is 

 quite doubtful whether the disease was observed in most of 

 the localities as soon as it made its appearance there, but 

 rather our experience has been that it was usually discovered 

 in a place when someone became interested enough to search 

 for it. 



Hosts, Resistance, etc. While the blight was first found on 

 our native chestnut, Castanea dentata, and most of the damage 

 has been done to this species, it was soon determined that other 

 species of Castanea were more or less susceptible to the disease. 

 Murrill (48, p. 27) in 1908 called attention to these hosts, as 

 follows: "It is now certain that the chestnut disease attacks 

 all species of Castanea, both native and cultivated, that occur 

 in this region, namely, Castanea dentata, the common native 

 chestnut, C. crenata, the Japanese chestnut, and C. pumila, the 

 chinquapin, found native from New Jersey to Florida." The 

 European chestnut, Castanea sativa, though not mentioned by 

 Murrill, is now known to be about as susceptible to the disease 

 as our native species. At first certain varieties of this, as the 

 Paragon, were thought to be more or less immune, but sub- 

 sequent observation has not shown any that possessed marked 

 resistance. 



Concerning the infection of the Japanese chestnut, Murrill 

 said: "This discovery is especially timely because of the fact 

 that the Japanese chestnut has been under observation else- 

 where in the vicinity of affected native trees, and has been 

 considered immune, so that it has been mentioned as a 

 desirable substitute for the native tree in some of our parks." 

 Metcalf also had noticed this apparent resistance of the Japanese 

 chestnut, and published a short bulletin (33) in February, 1908, 

 in which he says : "Observations made by the writer the past 

 year indicate that all varieties and species of the genus Castanea 

 are subject to the disease except the Japanese varieties (Castanea 

 crenata Sieb. & Zucc.). All of the latter that have been observed 

 in the field or tested by inoculation have been found immune. 

 This fact can hardly fail to be of fundamental importance to 

 the future of chestnut culture. Although the nuts are distinctly 



