228 
Cave, Ky. Mammoth Cave, as well as can be told by scaling on the map, is 
approximately 215 miles from Lafayette. It is conceivable, of course, that 
a wind-borhe spore from such a Peridermium could have started the in- 
fection of Silphiwm plants each year; but when we consider the likelihood 
that the two species do not belong together, and the fact that the rust was 
found in practically the same place both times, together with the fact that 
the host is a perennial plant, it seems more reasonable to think that the 
original infection was started by a stray spore, and that its further propaga- 
tion and carrying over the winters was accomplished in the uredinia! stage, 
either by surviving spores, or by mycelium in the living host. 
A somewhat similar case is that of Coleosporium Ipomoew, which has 
been collected repeatedly in Tippecanoe County since 1895 on Ipomoea 
pandurata. It occurs in great abundance and is doubtless to be found in 
practically all parts of the State where this host is found. The same thing 
is true for this species as for the preceding regarding the alternate stage 
and the possibility of the epidemics being started by seciospores, with this 
addition, that because of the more general distribution and greater common- 
mess of the fungus, it is much less likely to be started each year by 
seciospores. 
Voleosporium Vernonie, on different species of Vernonia, has for its 
wcial stage Peridermium carneum on Pinus Blliottii and P. palustris. It has 
a very wide distribution in the State, being represented in the Arthur 
herbarium from eight counties. The hosts of the secia according to Sud- 
worth” and Small” are both confined to an area south and east of central 
North Carolina and the north third of Alabama. This distance from 
Lafayette, as scaled on the map, is approximately 430 miles, a distance 
about 2.5 times as large as our maximum distance which we might expect a 
rust to migrate in a season. Moreover, it has been collected at Lafayette 
in different years as early as July 18 and July 24, which dates are early 
enough in the season to render it even more unlikely that the infections 
were developed, even indirectly, from seciospores of the same season. 
Coleosporium Campanule is a species occurring in Indiana on Campa- 
nula americana. The zcium is known as Peridermium Rostrupi and occurs 
on Pinus rigida in eastern Ohio. The closest approach of the range of the 
host to Lafayette, according to Sudworth’s map is in eastern Ohio, which is 
3°], c. Map 35. 
37Flora of the Southeastern United States 33. 1913. 
Forest Atlas. Geographic distribution of North American Pines. Partl. Map 26. 1913. 
