410 REPORT OF STATE BOARD OF HORTICULTURE. 



The pressure of other work prevented a more careful study of the matter, 

 however, until the past season. Specimens of Baldwin apples were then 

 examined, beginning with the first evidences of their spotting in the autumn 

 before harvest. The spots in the early stage of their development were 

 found to be covered with an unbroken epidermis and the diseased tissues- 

 were free from fung'ous invasion. 



Careful search was also made for bacteria in the browned tissues of the 

 spots and in the adjacent apparently normal tissues. This included both mi- 

 croscopic examinations and the transference with proper precautions of bits 

 of the tissue to various culture media ( bouillon, gelatin, agar, and special 

 media containing malic acid). 



In no case were bacteria found. There remained no doubt, therefore, in 

 our minds, that the spots were not due to the direct invasion of the tissues 

 by fungi or bacteria. 



Several facts of interest were observed, however, some of which had been 

 noted also in previous seasons. 



1. While the spotting was worse in case of Baldwins than with any other 

 variety in Vermont, it was not confined to this variety. It was quite com- 

 mon on Northern Spies and was observed also on Greenings. 



2. The spots were not uniformly distributed over the surface, but were 

 considerably more numerous toward the eye (apical portion) than toward the 

 cavity of the fi-uit (basal portion). 



3. The spots were not confined to the surface but appeared at various 

 depths in the flesh, the deeper ones often being overlaid by a half inch or 

 more of sound flesh. 



4. The spots were associated in their distribution with that of the vas- 

 cular bundles, occurring at or near the ends of the veins which permeate 

 the flesh of the fruit. 



Having opportunity at this stage of the study to confer with the officers 

 of tne Division of Vegetable Physiology and Pathology of the United States 

 Department of Agriculture it was learned that Mr. M. B. Waite and Dr. E. 

 F. Smith had made observations upon a similar spotting of apples which 

 they were satisfied was a non-parasitic disease, and which Doctor Smith con- 

 sidered identical with a dry-spot disease described by Wortmann occurring 

 in Europe. 



The examination of Wortmann 's paper* leave.s no doubt that the disease 

 discussed by him under the name "Stippen " or " Stippich-werden " is iden- 

 tical with the brown spot of the Baldwin, although the Baldwin did not 

 chance to be among the varieties included in his studies. 



Wortmann 's work has been recently critically reviewed and his conclu- 

 sions reaffirmed and somewhat extended by Bschokkef. Numerous experi- 

 ments were devised and conducted by Wortmann and others by Bschokke in 

 connection with their studies which satisfied them of the correctness of their 

 conclusions. 



♦Wortmann, Ueber die sogenannte, "Stippen " der Aepfel. Ijtmdw. Jahrb., 21, pp. 

 H63-675 (-J892). 



tBscholike, I.tiudw. Jahrb. d. Schweiz, II, p. V.)2 (1S!I7). This author gives a veiy conv 

 plete bibliography of the German literature of the disease. 



