60 EXrERBIEXT STATION. [Jan. 



firm is in a (inandary as tu what to do. When one Las a vunnu' 

 orchard with 50 per cent, or more of the trees afiected, the ques- 

 tion arises as to what should be done with it. It is possible, 

 also, that one might obtain stock from a nursery free from galls, 

 yet the soil from which they were taken may have been contam- 

 inated, and in this way the disease might break out later, when 

 the stock was transplanted. Even though it is not certain that 

 crown gall on fruit trees is of serious consequence, affected trees 

 ai-e certainly not in a normal condition, and the functions of the 

 tr(>e must be more or less interfered with, since the conductive 

 tissues in the galls are to a greater or less extent misplaced and 

 contorted, according to the severity of infection. There is, 

 moreover, a risk in planting trees affected with gall, since one 

 can never know when some complicated trouble may arise, 

 owing to the presence of such malformed tissue. 



There is a great deal known in regard to the effects of galls 

 on plants in general, and it is known that they cause much 

 injury. 



The writer has devoted many years to the study of galls 

 caused by eel worms (Ileterodera). Some plants affected with 

 eel-worm galls present few abnormal features as regards vigor 

 and yield, while others become sickly, and many die outright. 



Tomatoes grown under glass are often affected quite severely 

 with galls caused by eel worms. These very rarely, if ever, kill 

 the plant, and in the great majority of cases, so far as we have 

 observed, do not affect them severely. On the other hand, 

 cucumbers appear to be often seriously affected, and while many 

 ])lants will live when the roots are covered with galls, others will 

 die. and the yield is, in practically all cases, materially reduced. 

 Aiuskmelon plants are even more severely affected with eel-worm 

 galls than cucumbers ; to such an extent, in fact, that it is seldom 

 that an affected plant is not killed before reaching two or throe 

 feet in length. The roots of roses are also susceptible to eel 

 worms, which form almost microscopic galls, and often reduce 

 the productiveness of this crop 75 per cent. A considerable loss 

 of money has been experienced by rose growers from this cause. 

 This is also true of violets. According to our own exj^eriments 



