IMMUNITY PEACH ON PLUM. 39 



five trees were carefully located and have been under observation ever 

 since. I examined them particularly May 23, 1890, making the follow- 

 ing memoranda : 



The character of the trees from which carae the buds used in working the peach on 

 plum roots is as follows, all of the buds of one variety having been taken from one 

 tree : 



(1) Old Mixon. Exact origin unknown ; set out by T. A. Smith, of Deiiton; age, 

 38 years; entirely free from yellows; foliage of a healthy green. 



(2) Crawford's Early. Budded by Mr. Kerr from a bearing tree in Caroline County; 

 set in 1874; entirely free from yellows ; foliage vigorous. 



(3) Mountain Rose. Budded by Mr. Kerr from a bearing tree! n Caroline County ; 

 set in 1876 ; entirely free from yellows; foliage vigorous. 



(4) Crawforffs Late. Budded by Mr. Kerr from a bearing tree in Caroline County ; 

 set in 1876 ; entirely free from yellows; foliage vigorous. 



(5) Beers'' Smock. Budded by Mr. Kerr from a bearing tree in Caroline County, 

 set in 1876 ; entirely free from yellows ; foliage vigorous. 



These trees are old and broken, but they are not diseased. 



The entire orchard was examined at that time. It contains about 

 500 trees. They remind me of trees in the old orchards at Seaford? 

 Delaware. Like them they suffered severely during the winter of 

 1881-'82, * and are rough, broken, shaggy with lichens, and frequently 

 two-thirds dead. Here and there a tree is missing. Others have lost 

 their entire top, healthy growths from the trunk having partially taken 

 its place. The foliage on all was green and thrifty. There were no 

 cases of yellows and no suspicious trees. All of the younger orchards 

 on the same farm were likewise examined with a similar result. 



This experiment is the only one in which I did not superintend the 

 inoculations personally. At that time other duties engaged my atten- 

 tion, and having entire confidence in Mr. Kerr, I trusted it entirely to 

 him, being assured that all the details would receive his personal at- 

 ention. 



Yellows has never appeared in any orchard on his farm, or in any on 

 the adjoining farms ; was not reported from Caroline County until 1887 

 is still rare in that county ; and is not certainly known to occur any 

 where in the immediate vicinity of Dentou. If cases do exist at Den- 

 ton, they must be sporadic antf rare. Otherwise I must have seen them 

 or heard of them. Such being the conditions, I could at the date of 

 these inoculations think of no place where one would be more likely to 

 secure buds free from any taint of yellows. 



A hailstorm in June, 1889, destroyed the tops of many of these trees. 

 The remainder were removed from the nursery in November of that 



* The severity of that winter killed the dormant peach buds in Caroline County, 

 Maryland, a thing never known before or since. It also injured the wood of many 

 limbs. The same injuries occurred at Seaford, Delaware. However at neither place 

 did yellows supervene, and the belief that this disease is due to autumn frosts or 

 severe winters is wholly untenable. There is not one fact offered in support of this 

 view which may not be explained equally well in other ways. 



