320 TIIK KL'SIS or N'OVA SCDTIA. — FKASEIi. 



The iii'cdiiiiospoi'c is priniai'ilv a spore for tin- i'a])i<] dis- 

 tribution (if llic fiiiig-iis So that it may re])C;tl, that is the 

 iiredosjxtrcs may iiit'cct the liost phiiit. ( )t't('ii the lirst formcil 

 generation whieli appears in early s])iMnii i'nil (irii>inatcs either 

 from basi(lios])()i-e infeetinn. aeciosporcs, or from i)o,reiinial 

 myoelium, are calleil ••|)iin)arv" nredinia. and the second 

 i^eneration which deNclops from ni'edospore infection are called 

 '"secondary" nredinia. The primary nredinia are usually 

 larger and more richly coloured, as in ruccinia ohiegens. 



In countries where the aecial host is absent and the 

 iirediniospore ])ro})agates the fungus, there is a tendency to 

 abundant development of this stage, as in Puccinia graminis in 

 Australia. This rust has lost the power to infect the barberry 

 there and urediniospores are produced abundantly, almost to 

 the exclusion (»f the t( liospoi-es. 



Urediniospores i-etain their germinating power for some 

 time. Bolley states that the uredospores of P. graminis in 

 certain cases may survive tlie winter even in N^orth Dakota, 

 ami thus cari'v the fungus oxer that ])erio<l. 



, I iiijiluspores. 



Another kind of ui'eiliniosporc which has thi<'keiie(l walls 

 and persistent or sid»])ei'sistent ])edicels is found in some species 

 of gramineous rnsts. The sori resend>le telia and the spores 

 have been mistaken ])y some ol)servers for teliosporcs. They 

 can be sep;ii'at(Ml from the true teliospoi-es by the presence of 

 several gerin-]K»res. riiey ha\'e Iteeii gei'minated in 1901 by 

 Oarleton and later liy Arthur. ;ind the germ tid)e of the 

 uredinios|)orc was thi' i-esnit. Thev have nut l)ei'n found in 

 any s|)ecies re])resented in Xova Scotia. 



Ai-thur states that they Ixdong to species having their main 

 development in arid or semi-arid regions. They occur only in 

 the United States and Mexico, except one species in India. 

 Arthur CP'ull. Torr. Dot. Club 32: 35. 1905) gives a list of five 

 species which he found to possess amphispores. All are from 



