302 BOTANICAL GAZETTE [APRIL 
He maintains that after taking into consideration the studies and observa- 
. tions of MArsHALL Warp and PLlowricut in England; McALpine and Coss 
in Australia; Bottey, HircHcockx, and CaRrLeTon in North America; BaRr- 
cLay in India; KLEBAHN, DreTEL, SCHROETER, and MAGNus in Germany; 
LAGERHEIM in Sweden, and others, the wintering of the uredo-bearing mycelium, 
or of the uredospores, so as to be a source of infection for the coming season, 
has not been proven. The evidence, chiefly as brought forward by KLEBAHN, 
to show that the first appearance of the rust in spring can often be accounted 
for by uredospores being carried long distances by the wind, is reviewed, and 
the conclusion reached that this is an assumption based on no direct evidence 
and highly improbable. 
The author then enters upon the vital part of the subject and discusses the 
mycoplasm theory and its recent criticism, especially that which has been most 
ably presented by KLEBAHN and MarsHALL Warp. After an extended examina- 
tion of the works of these authors, he finds that his theory has not been affected. 
He directs attention to a report by BIFFEN of recent experiments in hybrid- 
izing wheat carried on at Cambridge, England, in which the appearance of 
rust on the plants can best be explained by assuming that the mycoplasm of 
certain varieties was transmitted through the pollen to the resulting hybrid. 
—J. C. ARTHUR. 
Gynodioecism.—CorrENS? “has presented a second® report on the gyno- 
dioecism of Satureia hortensis and Silene inflata, giving full confirmation of his 
earlier conclusion that the pistillate form produces only, or mostly, pistillate 
offspring when fertilized, as it must be, by the bisporangiate form. If the pis- 
tillate form is a mutant from the bisporangiate and differs from the latter by the 
possession of a distinct hereditary unit, as suggested by Burck,® all the seeds 
produced by a pistillate plant are of hybrid origin, and the observed facts would 
be best explained as a case of dominance of the newly risen character over the 
older. In Satureia this dominance (?) is complete, but in Silene the offspring 
of the pistillate plants were pistillate in only 87-93 per cent., the rest being bi- 
sporangiate. Although this behavior looks very much like Mendelian inheri- 
tance, a number of cases are cited in which quite contradictory results have 
been obtained, so that while the author states it as a law that each sex has a 
tendency to transmit its own sex form, he does not look upon this as dominance 
in the Mendelian sense—Grorcre H. SHULL 
An ear of corn.—The origin of such economic plants as wheat and maize, 
which have a wide distribution in cultivation but are unknown in the native 
tis Bot. GAZETTE 39:304. Ap. 19 
, C., Weitere cae iiber die Gynodioecie. Ber. Deutsch. 
Bot. Gesell. aie 452-463. 1905. 
, W., Die Mutation als Ursache der Kleistogamie. Recueil Trav. 
bot. pee I-2:95 sqq. 1905. 
