PEACH YELLOWS AND PEACH ROSETTE. 195 



In one or two instances only, I heard of premature peaches, but on exam- 

 ination they were clearly attributable to borers and not the sort produced 

 by yellows. In one orchard where the borers had been left undisturbed 

 for several years, I saw fruits prematuring on many trees, but there were 

 no symptoms of yellows. The color and flavor of these fruits was natural 

 and they were ripening only a week or ten days in advance of the proper 

 time. 



(d) Boots and rootlets. — Superficially the roots appear to be normal, 

 but the rootlets are dead and shriveled as in peach yellows. 



(e) Gummosis. — The green and shriveling fruits from rosetted limbs 

 were full of minute gum-pockets, but this symptom was afterward observed 

 quite frequently in imperfect fruits taken from healthy trees. The "June 

 drop" from Elberta trees was very copious at Griffin, Georgia, in 1891, and 

 most of these fruits were smooth externally but gummy within, the entire 

 seed-cavity being changed into a gum-pocket in many cases. These fruits 

 were an inch by inch and a half in diameter at time of dropping. 



Many of the roots of rosetted trees were honeycombed by gum-pockets 

 (June, 1891). This symptom was found to be nearly constant; i.e., it 

 occurred on some roots of nearly every affected tree. But it was also 

 observed to a slight extent on the roots of two trees which stand very near 

 diseased ones, but which have not yet developed any symptoms of the 

 rosette. Many of the roots were so gummy as to feel sticky when bruised. 

 By making a clean cut at right angles to the main axis of the root the 

 gum-pockets were frequently visible without the aid of a triplet, especially 

 when the oozing of gum was copious. These pockets were confined gener- 

 ally to the outer part of the wood cylinder, and in several cases, known to 

 have been healthy in November, 1890, the cylinder of gum-cavities was 

 confined to the wood laid down in 1891, or to the dividing line between 

 this wood cylinder and the next inner one, and did not extend into the 

 wood formed in 1890. 



These closed gum-poekets involve few to many wood fibers, and fre- 

 quently include the very resistant cells of the medullary rays. On cross- 

 section they appear like an interrupted ring, or like a necklace of triangular 

 beads, in which each member corresponds to a pocket. The base of these 

 triangular cavities was always nearest the pith. Occasionally two cylin- 

 ders of gum-pockets were observed, one in wood formed early this spring 

 when the disease first appeared in the trees and the other formed in wood 

 recently laid down. In a few cases they occured also in the bark. The 

 walls were brownish and irregular, with modified and frequently hyper- 

 trophied and projecting cells. These cavities appeared to be free from 

 mycelium and bacteria, and cultures from the walls and the exuding gum 

 gave no positive results. 



The roots of about fifty trees were examined for this symptom, but lack 

 of time prevented the examinations from being as extensive and complete 

 as desirable. 



(3) First appearance and present distribution. — So far as I can learn 

 by diligent inquiry this disease first appeared in Georgia about 10 years 

 ago. It may have existed longer, but satisfactory evidence of this is 

 wanting. It occurs in the middle and north part of Georgia quite generally, 

 but I have not observed it in South Georgia or in Florida, nor in South 

 Carolina or states to the north. 



This disease, or one very much like it, also occurs in Kansas. It 

 appeared at Manhattan in 1889, and is now quite prevalent in that locality 

 but has not been reported from other parts of that state. 



