-5— 



Fleure 2— Summer or Uredo spores of the rasp- 

 berry rust, Phragmidium rubi-idxi. Spore clus- 

 ter ^iirrouuded by club-shaped sterile bodies 

 paraphyses. (After Winter.) 



gones are absent and the spores are borne on stalks, from which they 

 easily fall, instead of being in chains. 



It is found that later in the sea- 

 son blackish winter spores follow 

 each of these forms and serve to 

 propagate the disease from year to 

 year. The one on raspberries is 

 Phragmidium rubi-idcei (Pers.) 

 Wint., and that on blackberries is 

 Pharagmidium rubi (Pers.) Wint., 

 the names being determined by the 

 winter spores. The yellow or summer spores of the two kinds differ 

 but little from each other, but the form on blackberries is a little 

 the more conspicuous. The winter spores are long, 

 cylindrical, nearly black and tipped with a sharp point. 

 The kind on blackberries is finely warty and divided by 

 cross partitions into five or six cells; that on rasp- 

 berries is coarsely warty and divided into seven to nine 

 cells. 



In this region the black raspberries are seldom at- 

 tacked, but the red ones, especially in a wild state, quite 

 commonly. The cultivated varieties of the red, Turner, 

 Brandywine and Cuthbert, are reported to have suffered 

 seriously from this disease at Jacksonville, Illinois. 



The yellow spores come in August or September and 

 the black ones soon follow. On the blackberry, the 

 yellow spores come somewhat later, and the black ones 

 have seldom been seen in this country. 



Figure 3- 

 raspberry 

 idsei. 



-Winter or telento-spores of 

 rust, Phragmidium rubi- 



