1918] CURRENT LITERATURE 373 
these rusts have their telial generations on species of Andropogon, and are 
distinguishable by evident morphological differences in their uredospores. 
P. Ellisiana has its aecidial generation on species of Viola, while the aecidial 
generation of P. Andropogonis occurs on species of Pentstemon. LONG now 
finds that P. Ellisiana will readily produce aecidia on Pentstemon also, but these 
aecidia resemble those of P. Andropogonis. More remarkable still is the fact 
that when plants of Andropogon are reinfected with aecidiospores of P. Ellisiana 
from Pentstemon, the resulting uredospores have all the characteristics of 
uredospores of P. Andropogonis. This rust can then not again be readily 
transferred to its original aecidial host, the violet. Conversely, P. Andropo- 
gonis can be made to infect species of Viola, but with great difficulty. If the 
aecidiospores thus obtained are sown on Andropogon, the resulting uredospores 
have all the characteristics of P. Ellisiana. In each case the morphological 
characteristics of the telial generation are determined by the aecidial host. 
From these facts the author concludes that P. Ellisiana and P. Andropogonis 
are but forms of one species. Since the transfer of P. Ellisiana to Pentstemon 
takes place readily, while the transfer of P. Andropogonis to Viola is accom- 
plished with difficulty, he believes that in nature the transformation of P. 
Ellisiana to P. Andropogonis through the aecidial host, Pentstemon, is continu- 
ally going on. The possible bearing of this discovery on the unexplained 
phenomena in the life histories of many rusts, and its consequent economic 
importance, are at once apparent 
Rust sori produced entirely within the tissue of the host do not seem to be 
of uncommon occurrence. To the number of known cases ApaMs” adds one of 
the occurrence of internal uredinia of Uromyces aan eee in the leaves 
of carnations, and CoLtey reports the finding of in telia of Cronartium 
ribicola in the petioles of infected currant leaves. t CoLLEy’s list of investi- 
gators who have reported internal sori of rusts should be added the names of 
BEAUVERIE, who described internal sori in the seeds of grains and other 
grasses, and of REYNOLDS,” who mentions internal telia of Puccinia Xanthii 
in the leaves of Xanthium canadense. 
In view of ARTHUR’s” recent revision of the rusts of the type of the orange 
rust on the blackberry in the United States, KUNKEL’s* paper, in which he 
clears up the anomalous situation created by his discovery” that the most 
7 ApAs, J. F., Internal uredinia. Mycologia 8:181-182. pl. r. 1916. 
* BEAUVERIE, J., Les germes de Rouilles dans l’intérieur des semencis de 
gramineés. Rev. Gen. Bot. 25:11-27. figs. 10. 1914. 
* REYNoLDs, E. S., Relations of parasitic fungi to their host plants. 
53: 365-395. 1912 (p. 381 
Bice, ae: J. C., Orange rusts of Rubus. Bot. Gaz. 68:501-515. fig. I. 1917. 
L, L. O., Further studies of the orange rusts of Rubus in the United 
Stati ‘Bull "Tow Bot. Club 43:559-5609. fig. r. 1916. 
* Rev. Bor. Gaz. 60:80-81. 1915. 
Bort. Gaz. 
