Root Troubles. 351 
he does not discover them in 
season. The various protec- 
tive washes which are ad- 
vised for keeping borers out 
of trees are of very doubtful 
efficiency. 
The roots of fruit trees 
and brambles are very likely 
to be affected with large tuber- 
like swellings or galls, which 
have been the subject of a 
good deal of mnneasiness in 
various parts of the country. 
One of these is shown in 
Fig. 64. So far as known, 
these galls are not conta- 
gious, and the amount of harm 
which they do has probably 
been overstated. The  root- 
knot of the southern — states 
and of greenhouses is a 
wholly different trouble, and 
is the work of a nematode 
worm. There is also a root 
swelling or gall on raspber- 
ries, due to the work of an 
insect. The nematode galls 
are commonly smaller and 
softer swellings, and occur on 
the younger or smaller roots, 
and appear not to occur in 
Fig. 64. Root gall on raspberry, 
(From Bull. 100, Cornell Exp. 
Sta.) 
