New York AGRICULTURAL EXPERIMENT STATION. 323 
A peach-tree disease.—In this connection it may be well to 
review briefly~a case of “Die back of the peach trees,” dis- 
cussed by F. M. Rolfs,4* where it is claimed to have been shown 
that Cytospora rubescens is an active parasite of the twigs, 
limbs and trunks of peach, plum, apricot and cherry trees. 
“Alternate freezing and warm periods” seem to favor the 
progress of the injury on peach shoots, often killing them back 
two to fifteen inches during January and February. ‘“-Infec- 
tions on the older branches during the winter-and early spring 
months produce oblong wounds extending up and down the 
stem.” 
“During the spring and summer months the foliage of in- 
fected twigs frequently wilts suddenly and takes on a brown, 
blighted appearance.” ‘ Large limbs or even whole trees in 
different stages of vegetation and at different times of the year 
die suddenly.” 
These observations can certainly be interpreted in another 
way, for they appear primarily to be winter-injury. 
Some other possibilities—It is well not to ride a good 
horse till it becomes a hobby, but there are two other matters 
that may be considered in this connection; namely, the little 
apples of this season, and the Bacillus blight of pear and apple. 
Perhaps it will prove profitable to find out whether such fruit- 
spurs and twigs, bearing clusters of small apples, have been 
winter-injured. A cursory examination of them has shown the 
presence of some browned cortical tissues around the bases of 
Some spurs, and often a more or less distinct brown line at 
the transition of last year’s into this year’s wood. It is gen- 
erally considered that plant lice and drought are the causes of 
this type of little apples, but that foregone conclusion may 
better be oriented somewhat in relation to this other probable 
factor. 
The virulence and destructiveness of the twig blight Bacil- 
lus have been so often observed and discussed that it has 
become a commonplace, but its manner of infection and of 
Science, N. S., 26: 87-9. 1907. 
