268 



COMPARATIVE MORPHOLOGY OF FUNGI 



To Septorisphaerella belong Mycosphaerella Hippocastani (Carlia 

 Hippocastani), a leaf spot of Aesculus Hippocastanum, and M. sentina, a 

 leaf spot of pear. As imperfect forms besides pycnia with multicellular 

 conidia (Septoria aesculicola) , Klebahn (1918) found in culture free 

 falcate conidia similar to Septoria conidia which are cut off laterally on 

 hyphae and also pycnia with very small bacilliform microconidia. 



Fig. 178. — Mycosphaerella sentina. 1. Pycnial stage. Septoria pyricola. 2. Part of 

 perithecial wall. 3. Perithecium. 4. Asci with ascospores. (1 X 236; 2, 4 X 550; 3 X 

 460; after Klebahn, 1908.) 



Septoria pyricola is the only imperfect form of M. sentina (Fig. 178, 1) 

 (Klebahn, 1908; Laibach, 1920). 



Of the section Ramularisphaerella, M. Fragariae, M. punctiformis 

 and M. Hieracii are worthy of note. M . Fragariae, a leaf spot of straw- 

 berries, has Ramularia Tulasnei (Schellenberg, 1917). M. punctiformis, 

 a leaf spot of Tilia, forms free conidiophores with catenulate conidia, 

 pycnia and perithecia. M. Hieracii winters over on Hieracium, like M. 

 Fragariae, with small black sclerotia which grow into the rind of the stem 



