242 
Journal of Agricultural Research 
Vol. XXV, No * 
We have no reason to suspect that the rust on the wild blackberries 
is in any way unlike that found on the cultivated blackberries, or that 
forms of the long-cycled rust on the bla.ckberry and on the black rasp¬ 
berry are at all different biologically, except that certain strains may prove 
to be more vigorous in their parasitism. As between the systemic stage 
of the short-cycled and that of the long-cycled rust as they occur on 
different types of host plants, and as between these and the teleuto- 
sporic or sporophytic stage of the Gymnoconia as it is found on black¬ 
berry, dewberry and the black raspberry, it must be expected that 
considerable difference will be found in the readiness with which par¬ 
ticular hosts can be infected. Later infection experiments tend to show 
that the Iceberg blackberry which is very susceptible to attack by the 
short-cycled rust from the blackberry, is very resistant to the rust 
from the wild dewberry. This short-cycled dewberry rust may be 
somewhat different biologically. 
LITERATURE CITED 
(1) Arthur, J. C. 
1917. ORANGE RUSTS OR rubus. In Dot. Gaz., V. 63, p. 501-515, map. 
(2) Atkinson, George F. 
1918. selected cycles in gymnoconia peckiana. In Amer. Tour. Bot., v. 
5, p. 78-83. 
(3) Clinton, G. P. 
1893. ORANGE RUST OP RASPBERRY AND BLACKBERRY. In Ill. AgT. Exp. Sta. 
Bul. 29, p. 273-300, 4 pi. Literature, p. 292-295. 
U) —— 
1920. NEW OR UNUSUAL PLANT INJURIES AND DISEASES POUND IN CONNECTI¬ 
CUT, 1916-1919. Conn. Agr. Exp. Sta. Bul. 222, p. 397-482, pi. 33-56. 
(5) Dodge, B. O. 
1923. THE distribution op the orange-rusts op rubus. In Phytopathol¬ 
ogy, v. 13, p. 61-74. Literature cited, p. 74 
(6) Hunt, N. Rex. 
1919. THE “iceless refrigerator” as an inoculation chamber. In Phy¬ 
topathology, v. 9, p. 211-212, pi. 12. 
(7) Kunkel, L. O. 
1920. FURTHER DATA on the orange-rusts op rubus. In Jour. Agr. Re¬ 
search, v. 19, p. 501-512, pi. D, 92-94. Literature cited, p. 512. 
(8) Newcombe, F. C., and Galloway, B. T. 
1890. perennial mycelium of the fungus op the blackberry rust. In 
Join-. Mycol., v. 6, p. 106-107, pb 5-6. 
