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On THE HetTERoEcIOUS Pant Rusts or INpIANA. 
By AARON G. JOHNSON. 
In the study of any organism, a knowledge of its life history is one 
of the things of first interest. Particularly is this true in the study of the 
heteroecious plant rusts, exhibiting, as they do, alternating phases on 
entirely different host plants. The complexity, which these plant parasites 
present, adds varied interest to their study, although the same complexity 
offers abundant obstacles in determining the connection of the various 
forms. 
It is the purpose of this paper briefly to show what has been done 
in the way of connecting forms represented in the State, and what re- 
mains to be done in this particular line. In presenting the unattached 
forms, particularly the unattached aecia, it is hoped to help engage the 
interest of others in assisting in any way possible in properly connecting 
up these forms. The three lists given below show respectively the con- 
nected forms, with the authorities and dates of connection for each 
species, the unattached telial forms, and lastly the unattached aecial 
forms. The first two tables are based on Dr. Arthur’s Revised List of 
Indiana Plant Rusts (Proc. Ind. Acad. Sci. for 1908.) For convenience, 
the familiar genus names Uromyces and ,.Puccinia are used, the species 
names, as far as possible, being revised to date. The third table is based 
on specimens in Dr. Arthur’s herbarium, as are also the aecial forms ap- 
pearing in the first table which have been connected up since the pres- 
entation of Dr. Arthur’s list. For host names Britton’s Manual (2nd. Ed.) 
is followed. The sincere gratitude of the writer is here expressed to Prof. 
J. ©. Arthur for access to his very valuable herbarium as well as to his 
extensive library. Most able assistance was also given throughout by 
both Dr. Arthur and Mr. F. D. Kern, for which the writer is very greatly 
obliged. 
The life histories of thirty-four species of heteroecious rusts repre- 
sented in Indiana are now known. The aecial stage, however, of nine 
of this number is not known to occur within the State. In some cases 
