o8 NATURAL HISTORY BULLETIN. 



a. Asci with stalk-cells. 



Taphrina aiirca ( Pres. ) Fr. 



h. Asci without stalk-cells. 

 ". on floral organs. 



Taphrina johansonii Sadeb. 

 Taphrina rhizophora Johanson. 



,1 on foliage leaves. 



Taphrina carnca Johanson. 



Taphrina ctxndcsccns (Mont. & Desm.) Johanson. 



[ Taphrina zirgi^iica Sadeb. j 



^Taphrina cesciili Ellis tS: Everhart.] 



2. The fertile hvpha^ not completely used up in the for- 

 mation of asci. 



Asci with stalk-cells. 



Taphrina ulnii i Fuckel) Johanson. 



B. Mycelium and hymenium development only within the 

 epidermal cells {Taphrinop<is\. \ No American form.] 



M A G X L' S 1 E L L A. no v. gen. 



The vegetative mvcelium spreads particularh' in the inner 

 tissue of the infected parts of the plant and sends thence 

 branches to the surface of the host-plant. The ends of these 

 branches swell verv considerably and each develops into an 

 asms. The Inphal form from which the asci arise occurs 

 between the epidermal cells or intercellularly still deeper in 

 the inner tissue of the host-plant. The differentiation of the 

 stalk-cell has not vet been noticed in these asci. The asci 

 arise from no universal hvmenium but stand sino/y: the\' have 

 more than four spores and develop conidia in their interior 

 while the ascus is still closed. The conidia of most species 

 are very small. The infection is confined to larger or smaller 

 spots on leaves and occurs only seldom on the stems. Many 



