APPIvE DISEASES. 197 



masses. The spores agree in shape, size and appearance with 

 spores from the pycinidia on decaying apple. On sterilized 

 potato cylinders in tubes after 5 days, the slants were covered 

 by the mycelium and some white serial mycelium had developed. 

 After 9 days small compact masses could be noted from which 

 drops of clear liquid were exuding. Twenty days from the 

 time of inoculation, mature pycnidia were found from which 

 the spores were exuding in the manner described for bean pod 

 cultures. On sterilized apple wood the fungus grew slowly 

 producing a thin network of mycelium over the wood and later 

 a small amount of white serial mycelium. The mycelium did 

 not extend much into the liquid but formed a rather thick crust- 

 like pellicle. Where the mycelium came in contact with the 

 liquid, the hyphse took on a light brown color. Three weeks 

 after the tubes were inoculated a few pycinidia had developed 

 on the wood and compact masses of hyphas such as have been 

 described as occurring on other media were seen. 



In June, 1909, small apple branches which were dying back 

 were collected in an orchard in Orono and also in Monmouth. 

 On examination, a fungus was found which agreed in its char- 

 acters with the one described above. 



In order to determine the extent to which the fungus could 

 cause disease of the wood, 2 of the young apple trees such as 

 were used in the work with Coryneuin were inoculated with 

 material from pure cultures growing on bean pods, May 17, 

 1909. Nine places were inoculated and 2 check incisions were 

 made. One week after the time of inoculation, it could be 

 noted that the fungus was growing at all the places which had 

 been inoculated except one which was as clean and bright as 

 the checks. June 2, there were areas of dead brownish bark 

 around the 8 inoculated places. June 9, it was noted that the 

 areas of dead bark had increased to some extent; and that the 

 cankers resembled those caused by Coryneuin. A more care- 

 ful examination showed that a few pycinidia had developed on 

 the dead bark near the incisions and the spores in these pycnidia 

 agreed with spores from decayed apple and from bean pod 

 cultures. June 17, some of the branches were almost girdled 

 but in some cases callus was forming which checked the spread 

 of the fungus to some extent. August 2, the cankers were 2-5 

 cm. in length and a considerable number of pycnidia were found 



