GYMNOSPORANGIUM. 



397 



the species already described in remaining closed at the apex, 

 the spores escaping through trellis-like slits on the lateral walls 

 of the peridia (Fig. 234). 



This fungus will not germinate on apple-trees, but on pears 

 every leaf may be thickly covered with aecidia and pycnidia, 

 and considerable damage to the crop thereby ensue (Fig. 233).. 



Pig. 231. — Longitudinal section through 

 a conical teleutospore-sorua of Gynmo- 

 spofrangium Satnnae. (After Woemle.) 



Fig. 232.— Teleutospores of G. sabinae. 

 The elongated thin-walled ones are 

 lighter in colour than the thick -walled. 

 (After Woemle.) 



Infections on various hosts with Gymno^orangium sabiriae 

 from Juniperus Sabina gave : 



On Host-plant. 

 Pyrus communis, 

 Crataegus Oxyacantha, 

 Mespilus germanica, 

 Pyrus communis, 

 Pyrus communis, 



„ Michauxii, 



„ tomentosa, 

 Pyrus communis, 

 Pyrus communis, 

 Crataegus Oxyacantha, 



Spore-form. 



(?) 

 Rostelia cancellata, - 



Authority. 



Plowright. 

 Oersted and Be Bar y. 

 Edthay, Tubenf, etc. 



Keess. 



E. Fischer. 

 Klebahn. 



,, (uncertain). 



