The UredinecB. 
129 
A SHORT REVIEW of the GENERAL CHARACTERISTICS 
AND CYTOLOGICAL PHENOMENA of the UREDINE^E, 
WITH 
NOTES ON A VARIATION IN THE PROMYCELIUM OF 
COLEOSPORIUM PULSATILLA (Str.) 
By James R. Weir. 
JHE Uredinese comprise a large group of parasitic fungi, of 
somewhat doubtful affinities. That they are closely related 
to the Basidiomycetes will be pointed out during the progress of 
this paper and their possible relation to the Rhodophyceae will be 
indicated. The Uredineae are characterized by a lack of an evident 
sexual generation, by the number of different kinds of asexual 
spores they produce and by their heteroecious habit. The mycelium 
unlike some of the other parasitic fungi is always found within the 
tissue of the host plant deriving its nourishment by means of 
haustoria sent into the host-cells. 1 
The fruiting of the fungus is characterized by the production 
of a variety of spores, typical of the season in which they are 
produced, also by the fact that the spores are often incapable of 
producing infection unless they be transported to a different host- 
plant. The spores typical of the late stages in the life-history are 
known as teleutospores. [It is the ultimate condition always 
present.] They are found in sori and ,are usually tough-coated 
resistant spores as they furnish the chief means of tiding the fungus 
through the winter condition. They are popularly spoken of as 
winter spores. These spores lie dormant throughout the winter and 
in the spring germinate to form spores which on the proper host will 
produce new infection. 
The stage of the rust arising from this infection produces its 
spores as conidia in cluster cups, and for many years botanists 
regarded this as a separate and distinct fungal species. This stage 
is known as the tecidial stage. The aecidiospores are produced in 
great numbers and greatly spread the infection. These spores will 
not produce infection unless they reach the proper host-plant when 
they give rise to the next stage characterized by the production of 
uredospores, the so-called summer spores. This same mycelium 
during the latter part of its course produces the teleutospores. It 
