386 



UREDINEAE. 



The aeeidia are developed about the beginning of June, and 

 on Crataegus their peridia in dehiscing split up into very- 

 narrow lobes so as to form a bristly tuft over the mouth of 



each aecidium. On cultivating infected plants of Crataegus 

 indoors, I found the peridia to develop quite abnormally; they 



