Ill 



kinds of the American plums. Here at Ames I have noted it on the 

 following species and varieties: Pattowattamie {Pn/Niis augusfifolia), 

 Miner {Pruniis Iwrtulaiia^ var. iMnieti), Maquoketa, DeSoto, Rolling- 

 stone, Speer, Chippeway, Flack Hawk, Hen Plum {Pruiius Americana), 

 Sloe Plum {Pnouis spiiiosa). Mr. F. C. Stewart reports this fungus at 

 Greenfield, Iowa, on wild and cultivated plums, in some cases it 

 ruined half the crop. I have also seen it very common on wild 

 plums at Cedar Rapids, Iowa, and Mr. Stewart also found il at 

 Marshalltown, Iowa. Mr. Geo. W. Sturtz reports it at Plainview, 

 Nebraska, and Mr. John Wragg at Nankee, lovva, and my friend, Prof. 

 Craig, of Ottawa, Canada, writes me that it was common in Minnesota 

 on cu'tivated Cheney, DeSoto, Rollin^jstone and Speer; That it also 

 occurs on the common Wild Plum and cultivated varieties in Canada ; 

 also in Virginia on P. Americana. It did not appear at the Experi- 

 mental Farm, Ottawa, in 1891. From this it will be seen that 

 this fungus has become widely distributed and destructive. The 

 disease is certainly on the increase. It did not appear to any 

 extent this year here at Ames, except upon a few chickascav; and 

 s'oe plums. As j^lums fruited but little, I have not seen it attack- 

 ing Prunus do?7iestica at Ames. The Cladosporiian has become a 

 serious enemy to cherries, first noticed in 1891 when it destroyed from 

 2 to 10 per cent, of the crop. First appearance is marked by a pale 

 coloured spot not larger than a pin head, which increases in size, and 

 finally is olive green in colour. As in plums a crack is frequently found 

 extending across the patch. The cherries are also badly shrivelled in 

 many cases, some.vhat bitter and sour. We noticed the following 

 varieties affected in 1891 : Cerise Ostheim, Spate Amarelle, Shadow 

 Amarelle, and Wagner, and in 1892, although the cherry crop was 

 small, the disease appeared on many cherries ; my assistant Mr. Stewart 

 has furnished me with the following list : Lutooka, Shadow Amarelle, 

 Schatten Amarelle, Spate Amarelle. It will be noticed that this list 

 only contains Russian varieties. Most of the cherries grown on the 

 college grounds are Russian. Early Richmond growing not far from 

 the college was not affected by the disease ; it may have appeared in other 

 places, but I have not heard of any, or at least specimens were not 

 sent to me. Experiments with fungicides would have been made this 



