A MONOGRAPH 



OF THE 



BRITISH 



UREDINE^ AND USTILAGlNEili. 



CHAPTER I. 



BIOLOGY OF THE UREDINE^ — INTRODUCTORY REMARKS. 



The Uredineae constitute a large and important group 

 of parasitic fungi, affecting flowering plants and ferns, 

 representatives of which are familiar to every student of 

 nature, practical agriculturist, and working microscopist. 

 In whatever part of the world phanerogams appear, these 

 parasitic cryptogams accompany them. 



Our present object is to obtain an insight into the life- 

 history and the structure of those species which are known 

 to occur in Great Britain. Much has been elucidated con- 

 cerning these points during the past twenty years, but still 

 much remains to be discovered. 



They all grow as parasites upon some living plant, 

 independently of which they cannot exist, and consist 

 of two essential elements — spores and mycelium. 



The spores every one sees ; the mycelium, on account 

 of its inconspicuous nature, and because it cannot be seen 

 without some little effort, no one takes the trouble to look 



B 



