410 BOTANICAL GAZETTE [DECEMBER 
without calling upon any other effective elements than the ‘“‘orthodox”’ factors 
of inheritance that are located on the chromosomes. In the third place, the 
theoretical possibility of artificially controlling sex is illuminated. Such control 
should be possible to the degree that the ordinary heritable characters can be 
successfully duplicated artificially. The fact that the fourth chromosome 
which is known to contain relatively few factors) 3 is preponderant in its 
influence poe maleness suggests that a few ifi y be preponder 
ant in influence. Artificial control, therefore, should necessitate the duplica- 
tion of the effects of only a few of the factors. Also, the identification of 
particularly effective heritable factors should be followed by the establishment 
of a race with a heritably distorted sex ratio—M. C. CouLTER. 
Taxonomic notes.—B¢RGESEN,’ in continuation of his studies of the 
marine algae of the Danish West Indies, has completed the Rhodophyceae. 
These two concluding parts include ror species, four of which are new, dis- 
_ tributed among 29 genera. The following three new genera are established: 
Cottoniella, Coelothrix, and Hypneocolax. An extensive appendix (86 pp.) 
gives a list of the Chlorophyceae, Phaeophyceae, and Rhodophyceae found 
at the islands, together with addenda and corrections. 
ENGLER’ and his collaborators, in continuation of their studies of the 
African flora, have published the following results: U Lpricu describes 4 new. 
species of Pavonia; Mez describes 94 new species of grasses, 33 in Panicum, 
33 in Melinis, and 18 in Digitaria; ENGLER describes 16 new species of Gesnera- 
ceae, 14 of which are in Streptocarpus, and also establishes a new genus (Cleno- 
cladus) of Moraceae; Wotrr describes 19 new species of Umbelliferae and 
establishes Caucaliopsis as a new genus; KRAvusE describes 8 new species of 
Liliaceae; IRMSCHER describes 7 new species of Begoniaceae; and BITTER, in 
continuation of his monograph of African Solanum, has reached 56 species. 
RyDBERG?, in continuation of his work on the Rosaceae, has presented 
the roses of the Columbia region, which includes Oregon and Washington, 
together with British Columbia and northern Idaho. In this region he recog- 
nizes 37 species of Rosa and nine hybrids. 
SCHLECHTER,” in reorganizing the classification of et ape pape 
35 species of Spiranthes and establishes 16 new genera as follows, chiefly from 
Mexico, the West Indies, and South America: Galeottiella, Hapolorchis, 
7 BéRGESEN, F., The marine algae of the Danish West Indies. Rhodophyceae 
(sand 6). Dansk Botanisk Arkiv 3: 305-408. jigs. 308-435. 1919 and 1920. 
8 ENGLER, A., Beitrige zur Flora von Afrika. XLVIII. Bot. Jahrb. 75:161- 
301. 1921. 
9 RYDBERG, PER AXEL, Notes on Rosaceae. XIII. Bull. Torr Bot. Club 48: 
159-172. 1921. 
%0 SCHLECHTER, R., Versuch einer cies ies Oe ei der Spiranthinae. 
Beih. Bot. Cestraine os: 317-454. 1920 
