24 MAINE AGRICULTURAL EXPERIMENT STATION. I9I4. 



observed.* Certain observations made during the past year by- 

 Mr. W. H. Darrow while working in this laboratory not only 

 show that the fungus which is said to cause this disease is pres- 

 ent in this State but that in some localities it occurs with com- 

 siderable frequency. Several specimens identical in appearance 

 with the descriptions and illustrations of canker said to be 

 caused by Nectria ditissima were collected. These varied from 

 small ones an inch or two in length to old ones 7 or 8 inches 

 long. Figs. 3 and 4 show some of the specimens olbtained. 



In one young orchard they were found on the trunks of 

 several trees while in older orchards the cankers appeared more 

 abundant on branches an inch or two in diameter. Several of 

 these cankers were foimd in crotches, suggesting that they 

 might have followed winter injury. The larger part of them, 

 however, showed the remains of a dead twig in the center indi- 

 eating that the fungus may have gained entrance thereby. 



The fruiting bodies of Nectria ditissima were quite constantly 

 found on the older of these cankers and the ascospores found 

 "within these perithecia and the conidia produced in cultures 

 agreed with the published descriptions of the fungus. This 

 determination was confirmed by Dr. J. J. Davis of the Univer- 

 sity of Wisconsin who very kindly examined some of the ma- 

 terial. 



From cultures of the fungus isolated from some of the can- 

 kers Mr. Darrow made a limited number of inoculations of 

 apple branches out of doors in May. These branches were 

 about one-half inch through, and on this date, December i, in 

 all cases points of inoculation have every appearance of the be- 

 ginning of a canker. The wounds, which were slight slits in 

 the bark, have not healed but have enlarged — some of them 

 covering from one-third to one-half the circumference of the 

 limb. In one or two instances the limb itself was enlarged at 

 the point of inoculation. 



* Morse, W. J., and Lewis, C. E. Maine Apple Diseases. Bui. Me. Agr. 

 Exp. Sta. 185: 371, 1910. 



