PLANT DISEASES IN 1908. 25 



than old trees. In fact, all other things being equal, the 

 younger the tree the more severe the injury. Large trees 

 only showed scattering tufts of dead needles and these 

 usually only on the more exposed sides. In severe cases the 

 twigs themselves were killed back several inches. In fact acres 

 of young trees in some parts of the State which were apparently 

 healthy in the fall of 1907 were entirely dead by the last of 

 May, 1908. The most characteristic thing about the trouble 

 was that the injury zvas usually confined almost wholly to the 

 north and northwest sides of young trees grozving in the 

 open or soniczvhat scattered. As a rule young trees occurring 

 in clumps or otherwise protected were injured only on the more 

 exposed parts. Young pines — 2 to 4 feet high — were frequently 

 observed early in May on exposed hillsides with the branches 

 on the north and west sides of the tree and the entire top dead 

 while the lower, more protected branches on the south side were 

 still green and apparently uninjured. 



Young pines which were badly injured when first seen in the 

 spring were kept under observation during the summer and 

 except in the few cases described later in this article zvhere the 

 trees, like those at Bninszvick, zuere plainly affected zvith an 

 entirely different trouble, there was no sign of disease on the 

 needles formed the present year. The old needles and injured 

 twigs gradually dropped off, and many trees by the first of 

 September had the appearance of being severely pruned ofif on 

 one side. About July first it was noted that in almost every 

 case adventitious buds were showing and little tufts of new 

 needles were forming near the base of the injury on each twig. 

 This is shown by the accompanying photograph (Fig. 4) 

 taken October 7. The new needles arc not so long as those 

 put forth in the spring but they are now (November 1908) 

 entirely healthy, with no signs of disease. 



Nor was this injury confined to the pines alone, for spruces 

 and firs and some other conifers showed the same trouble and 

 in the same manner. It was especially severe in the case of the 

 arbor vitcne. Hedges of this tree were practically exterminated 

 in some localities. 



Microscopic examination by means of sections of the needles 

 of afifected pines and other conifers failed to show any parasitic 



