88 



it may have been missed by collectors, as on Larix, for example, and may 

 subsequently be found; in others, however, it is doubtful if the aecia] stage 

 occurs here. In this case the species doubtless depends entirely upon its 

 urediniospores for reinfection of its host from year to year. Such, for 

 instance, is no doubt the case with the Poa rust (/'. epiphylla) and the 

 leaf rust of cereals and certain grasses (P. liubigo-vera) . 



In view of these facts it seems very doubtful that all of the sixteen 

 still unattached telial forms in the State have their respective aecia here. 

 In the first place, only nine unattached aecia are reported for the State, 

 though others may occur. In the second place, and apparently much the 

 better reason for the inference, of the thirty-four connected-up species 

 previously mentioned, only twenty-five have their aecial forms reported 

 for the State, while all of the connected-up aecial forms reported for the 

 State have their telial forms here also. This latter being very natural to 

 suppose for the teliospores are not readily transported by the wind or 

 otherwise, and the sporidia, which give the aecial infection, are very 

 perishable and entirely incapable of being blown very great distances and 

 still remain viable. Hence there seems little if any question but that 

 some unattached telial forms come into the State by uredinial infections, 

 and are thus kept up through the season and possibly even from season 

 to season in some cases. The aecia belonging to such forms may, there- 

 fore, be far distant. 



This condition, then, centers our interest in connecting unattached 

 forms, largely on the unattached aecia. For of necessity, their respective 

 alternate forms must be somewhere in the immediate vicinity of their 

 occurrence, except in the few cases where the aecial mycelium is peren- 

 nial, in which cases the forms may become somewhat separated. By care- 

 fully searching for and finding unattached telial forms, especially near 

 where the unattached aecia occur in abundance, clews may often be ob- 

 tained that may ultimately lead to proof of the genetic relationship of 

 such forms. 



The tables are as follows : 



