WINTER MEETING. 307 



The disease does not appear to be due to any ordinary fungus, or 

 to insects. In some respects it is quite like peach yellows, but in 

 others it differs very materially. This year additional observations 

 have confirmed the belief that it is a disease distinct from yellows, 

 and I shall so consider it until proof to the contrary is forthcoming. 



( 1 ) Plants attacked. — As stated elsewhere ( I. c). the Rosette 

 attacks many varieties of peaches. None appear to be exempt. It 

 occurs in budded fruits and seedling. The latter do not escape even 

 when growing in fields and thickets without cultivation. This disease 

 is not confined, however, to the peach, but also occurs in plums — bud- 

 ded trees and seedlings, cultivated, uncultivated and wild, and is equally 

 destructive. I have not seen it in varieties of Prunus domestica or in 

 the Mariana, but it occurs in the wild Prunus Chicasa, in the Cumber- 

 land and Wild Goose, and also in the Japanese varieties known as 

 Kelsey and Botan. Probably the disease is capable of attacking many 

 other sorts, and requires only a suitable opportunity. 



This year in an orchard near Griffin, Georgia, which I know to have 

 been nearly free from disease in 1890, and quite thrifty and well cared 

 for, I counted about 40 bad cases of rosette, divided nearly equally 

 between Kelsey and Botan. These trees were five or six years old, 

 ^.nd the loss must have been considerable. 



( 2 ) Characteristics of the disease. — As in peach yellows, this disease 

 not infrequently attacks one or two branches only at first, but in a much 

 larger per cent of cases the whole tree is diseased from the start, and 

 the disease runs its course in a much shorter time. Six months is 

 usually sufiBcient to destroy a tree, and I have known no cases to last 

 more than two seasons. Such a thing as the lingering on of a diseased 

 tree from year to year, as in peach yellows, is not known. I have seen 

 trees completely diseased in June and dead in November, which first 

 showed symptoms in early spring, and were in apparently perfect 

 health the preceding autumn. This is the common course of the dis- 

 ease. 



When a tree is attacked in part, the shoot-axes and foliage of the 

 remaining limbs often appear to be perfectly healthy, but these limbs 

 always develop rosettes, and die the following year. Not infrequently 

 I have observed the disease to progress gradually from the affected side 

 to the healthy — i. e., the parts on the healthy side first to be attacked 

 being the bases of the limbs. The bark of trunk and limbs on affected 

 trees presents no peculiar or symptomatic differences. Undoubtedly 

 there are changes in the cambium cylinder corresponding to the short- 

 ening of the terminal shoot-axes, but these are not visible externally. 



