364 CONNECTICUT EXPERIMENT STATION REPORT, IQI2. 



The Andersons (i) were among the last to study the rela- 

 tionship of D lap or the parasitic a to the genus Endothia. Their 

 studies having led them to believe that the blight fungus, 

 though related, was entirely distinct from Endothia gyrosa, they 

 have placed it under Endothia as E. parasitica (Murr.) Anders. 



Although the writer started out to prove the identity of the 

 chestnut blight with the Endothia gyrosa of Europe, he has 

 been forced to conclude from his microscopical, cultural and 

 inoculation studies that it is ttot exactly identical with that 

 species, as is held by von Hohnel and others. The relation- 

 ship, however, is so close that he cannot, on the other hand, 

 agree with the Andersons in considering it an entirely distinct 

 species. Hence he (9) has placed it as a variety under that 

 species, calling it Endothia gyrosa var. parasitica (Murr.) 

 Clint. 



The preponderance of opinion of those who have made a 

 critical study of the fungus, therefore, is that it is not an 

 entirely new species, but that it is merely a strain, or at most, 

 a variety of a previously described saprophytic or semi-parasitic 

 species, that for certain reasons has now attained unusual viru- 

 lence in the northeastern United States. 



CHARACTERISTICS OF THE DISEASE. 



As to the Host. It is easy enough to distinguish this disease 

 on the smooth bark of sprouts or young trees, Plate XXIII a, 

 since it forms definite cankers by killing the infected bark, 

 and these usually increase in size until the entire stem or limb 

 is girdled. These cankered spots are slightly sunken, and 

 distinguished from the healthy bark by a chestnut-brown color, 

 whereas the normal bark is more of a greenish-brown. Often 

 the bark on these cankered spots is more or less cracked, and 

 in time the fruiting pustules show as numerous minute cushions 

 projecting through lenticel-like openings. 



On the rough bark of the older trees the cankers do not 

 show very distinctly, though when cut out, as shown in Plate 

 XXIII b, they give a cankered effect. Frequently with these 

 the whole bark becomes infested, and the presence of the 

 fungus is shown by the fruiting pustules breaking out from 

 the deep cracks of the bark. Often when these do not develop, 



