54 



THE AMERICAN NATUBALIST [Vol. LI 



so than most other species of the genus. By comparison with 

 other tables, it will be found that the galls are of a much smaller 

 size than on most other hosts. The number of positive inocula- 



TABLE II 



Summary of Artificial Inoculations on German Prune, Prunus domestica. 

 Concluded November 15, 1914 



6/18/14 

 6/29/14 

 6/29/14 



8/15/14 



8/24/14 

 8/24/14 

 8/31/14 

 8/31/14 



tions as given in Tables II and III, is probably somewhat greater 

 than it should be, as in making the estimate of the number of 

 galls on these resistant stocks, any small enlargement was 

 counted, and subsequent examination has shown that many of 

 these small enlargements have not further increased in size. 

 When a gall becomes established in a resistant variety, it makes 

 rapid growth and eventually forms one of good size. These 

 large galls differ from similar galls on peach and many other 

 hosts in that the gall is attached to a relatively small circum- 

 ference of the infected twig. The gall growth is often nearly at 

 3 Numbers that are preceded by an x were made on rapid growing twigs 

 of the current year of a seven-year-old tree. The other inoculations in a 

 young tree two years old from the nursery. 



