STATE POMOLOGICAL SOCIETY. 171 



not at all ; and Secretary Garfield reports Earl}' Harvest, Fameuse, 

 Rhode Island and Northern Spy as suffering in other parts of 

 Michigan. 



In "Wisconsin, the Fanoeuse is pre-eminent as scabbing badly, while 

 the Walbridge, Late Strawberry, Haas, Northern Sp3', fall and winter 

 Winesop, Roman Stem, Sweet Pear, Rawles Janet, Fall Stripe, 

 McMahon's White, Ben Davis and Talraan Sweet scab more or less 

 badly in wet seasons or on heav}', poorly-drained soil. 



Several correspondents believe that no variety is absolutely exempt 

 from the disease under all circumstances ; but they agree that Duchess, 

 Alexander, Golden Russet (and, in fact, all russels), Wealthy, 

 Pewaukee, Tetofsky, Red Astrachan, Sops of Wine, Plumb's Cider, 

 Utter, Bethlehemite, Fall Orange, St. Lawrence, Cole's Quince and 

 Lowell, scab much less than most varieties of the first list. Of about 

 one hundred Russians in Mr. Tuttle's nursery, onl}' a few scab to an 

 injurious extent. 



Some idea of the injury caused by the scab may be gathered from 

 Mr. Hatch's statement that in his locality (Richland County) 99 per 

 cent of Fameuse and Walbridge, 40 per cent of Haas, 20 per cent 

 of Plumb's Cider, 10 per cent of Pewaukee, 5-10 per cent of 

 Tetofsk}', and something less than 5 per cent of Duchess, scab in- 

 juriously in bad years. The total failure of the apple harvest in 1883 

 over a large part of the State is attributed to the leaf mildew and 

 scab bj' several correspondents. 



These two diseases of the apple are not new diseases, nor are they 

 confined to Wisconsin. The theory has prevailed with a few orch- 

 ardists that both result from the age and lessened vigor of their 

 trees, or from a sort of natural deterioration of certain varieties 

 through long cultivation ; but neither of these theories is accepted by 

 the best observers. The same diseases occur on the pear. On 

 either plant they are, so to speak, epidemic in seasons which are 

 favorable for their development and propagation. Like a widespread 

 outbreak of small-pox in a large cit}' where isolated cases have oc- 

 curred all the time, they appear new to many people, and, like the 

 small-pox epidemic, may require active, concerted and intelligent 

 measures to prevent extensive damage as a result of their thorough 

 establishment in the past two 3'ears. 



Both diseases occur the world over. The fungus on the leaf was 

 studied and described in 1833, by Wallroth, as Cladosporium dendrit- 

 icum. From the variability of its spores and its wide distribution, 



