oe clue whatever. So it comes about that the two halves of heter 
PRLEPER ARTICLES. 
CLUES TO RELATIONSHIP AMONG HETEROBCIOU 
PLANT RUSTS.* 
Gus collection and study of Uredineae are beset with a difficulty 
not found in connection with other classes of plants. A large number 
of species, principally belonging to the genera Puccinia and Uromye 
inhabit two wholly diverse species of host, and the form of the fun 
assumed upon one host gives no clue to the alternate form upon 
other kind of host. If teleutospores, for instance, are found upt 
grass, there can be nothing detected in the morphology of the rust 
sponding aecidiospores are to be looked for upon a monocot Of 
dicot, upon a liliaceous, ranunculaceous, or composite plant, or 
of some other family, upon a tree, shrub, or herb; in fact there 
ae species. are usually a separately and listed nee 
eerie t genera. 
a _ Probably most localities will furnish from a dozen to twe 
a species of aecidia, and per contra the same number of unattached 
__ tosporic forms. Or, to use the prevailing method of expression, 
os will be so many heteroecious species showing teleutospores, 
= “= number of ee aecidia. Yet it stands to —_ 
the small consideration at present giv 
1 ts to = aecidial forms i is unfortunate and 
oe ‘For: some time I hoe carried on successful cultures with the 
LS ain Uredineae, by which spores of one half of a species were 
one ventually Save rise to the spores of the other half of the same 
© accomplish this it is necessary to have a pretty clear ° 
oe “fee Btn Seto Amr, Dever mei gui 
oo te. 
