New York AGRICULTURAL EXPERIMENT STATION. 301 
however, Northern Spy, Greening and others were also affected. 
Though many injured trees had dead areas of bark on their 
trunks and large branches, in the spring of 1907, the most 
striking effect in an orchard of 1200-1500 twelve-year-old, Ben 
Davis and Stark apple trees, was shown at the crotches. It 
seems that about 75 per ct. of them were affected more or less. 
The dead bark of the injured crotches seemed recently killed 
and due neither to bacteria nor fungi. It appears that in 
most cases in which trees were not killed, crotch-injury was 
very conspicuous. It is thought that the accumulated ice in 
the crotches is the cause of the injury or canker. 
REVIEW OF LITERATURE ON FUNGUS INJURY TO 
FRUIT TREES. 
Several fungi of the hymenomycetous group are found more 
or less constantly about injnred or decaying roots and crowns 
of forest and other trees many of which are still living. Pos- 
sibly a few of these are true parasites, though most of them 
probably only disintegrate non-living tissues of injured or dead 
trees. For some reason or other strict inoculation tests were 
generally deemed unnecessary to determine the pathogeneity 
of these fungi, the nearly constant presence of a fungus on 
injured or dead trees of one or more species having often been 
accepted as proof sufficient. Yet it may mean nothing more 
than that certain types of non-living tissues are suitable sub- 
strata for certain fungi. 
Other fungi are commonly found on areas of dead bark of 
cankers of the trunks and branches of trees. It is often diffi- 
cult to determine what killed the bark, especially when exam- 
ined in mid-summer or later. 
FUNGI ON THE ROOTS. 
An extensive article on root-rots of trees was published in 
1896 by F. Cavara.!® It is there held that many supposed 
* Contribuzioni allo studio del marciume delle radici e del deperimento 
delle piante lJegnose’in genere. Staz. Sper. Agrar. Ital., 29: 788-814. 
1896; reviewed in Ztschr. Pflanzenkrank., 7: 360-1. 1897. 
