280 



PLANT STUDIES 



disease with great rapidity ( l-'ig. 350). Once it was thonglit 

 that tliis completed the life cycle, and the fungus received 

 the name Uredo. When it was known that this is but one 



\\'lu';it ni>t. showiiiL' n ynniiL^ liyplia foirint^' its way frDni tho Bnrfncf of a 

 li.'uf dnw II aiiiiiUL^ the iuitiiti\L' {.'f'lls, — AftLT H. JIaksilall W'AKI). 



stage in a polymorphic life histf)ry it was called tlie Uredo- 

 stage, and the spores iircdiisjjures, sometimes " summer 

 spores." 



Fn;. ^rj]. Wheal nist, sliuwint^ the \viiiter simrcs (trlciitosporcsV— After 

 H. ]\Iaksiiat,t. \\'ai:i>. 



Toward the end of tho summer the same mycelium 

 develojis sporophores which hear a,n entii-ely diifercnt kind 

 of spore (Fig. -.T.l). It is two-celled, with a very lieavy black 



