41 6 CONNECTICUT EXPERIMENT STATION REPORT, 1912. 



radicalis of European authors, but not of Schweinitz, and that 

 it was probably introduced into this country from Europe, and 

 has gradually spread from the original points of introduction, 

 its spread being facilitated chiefly by borers or other animal 

 agencies which produced wounds favorable for infection by the 

 fungus." 



Shear's reason for supposing that the chestnut blight was 

 imported from Europe was th^.t Endothia gyrosa occurred on 

 chestnut there, and he could not distinguish the American chest- 

 nut blight from this fungus. He, however, apparently did not 

 know that E. gyrosa (E. radicalis of some European authors) 

 also occurred on chestnut in this country. Further, he (66) was 

 misled by an incorrectly named culture received from Pantanelli 

 (supposed to be of European origin but later turning out to be 

 the real blight from America) with which he produced the 

 disease in chestnuts. 



Pantanelli (53) of Italy, who has recently made a study of 

 the European Endothia gyrosa and the American chestnut blight, 

 finds ( i ) that they are different in many small microscopic char- 

 acters; (2) that, while E. gyrosa varies somewhat in character 

 in Europe, there are no variations that correspond to the chestnut 

 blight type; (3) that the native E. gyrosa causes no serious 

 disease in Europe; (4) that the American chestnut blight, when 

 inoculated into chestnut in Italy, produces the disease. Natur- 

 ally he concludes that our chestnut blight cannot be of European 

 origin. 



To the above we might add the fact that European chestnut 

 grown in this country is quite susceptible to the blight, and it 

 would be rather difficult to explain its susceptibility in this coun- 

 try and its immunity to the native fungus there, unless environ- 

 ment really did bear some relationship to susceptibility and 

 immunity of the host, which is denied by Metcalf. 



United States. The writer's reasons for believing the chestnut 

 blight is native to this country may be summarized as follows : 

 (i) It has never been found in any other country. (2) It is 

 very closely related to Endothia gyrosa, apparently developing 

 from it as a distinct variety, and this species is a native fungus 

 in this country as well as in Europe. (3) The limits of distribu- 

 tion of E. gyrosa and the chestnut blight overlap at least in the 

 region covered by Washington, D. C, to southern Pennsylvania, 



