191L] PUBLIC DOCUMENT — No. 31. 61 



the yield of violets is greatly affected by these galls, and the 

 l)laiits often die outright. 



In conclusion it might be said that the effects of crown gall 

 (ui fruit trees may have been often exaggerated. There is a 

 ])robability of some young nursery stock affected with crown 

 gall developing into good trees, but clean stock should he ob- 

 tained from localities free from the gall, if possible. Many 

 States have laws for the purpose of excluding crown gall stock, 

 but this disease has become so common, and certain varieties of 

 nursery stock so scarce, that it is a question whether at the pres- 

 ent time Massachusetts nurserymen would he able to supply the 

 demand for clean material for contemplated orchards if a pro- 

 hibitory law were passed. 



