162 BOTANICAL GAZETTE [AUGUST 
Davis? has also devised a method for increasing the rapidity and total 
percentage of germination in Oenothera seeds. He places the seeds on pads 
of filter paper in Petri dishes, adding water until a surplus remains about the 
edge of the pad. The dishes, covers, papers, and water are all sterilized before 
the seeds are inserted. The dishes, covered and kept in shaded portions of 
the greenhouse, showed much more prompt and complete germinations than 
samples of the same seeds sown in soil. The author notes that after periods 
of high temperature there followed a burst of germinations, and believes that 
the best results will be secured by subjecting the dishes of seeds to high tempera- 
tures in an incubator. Davis points out as one of the distinct advantages of 
his method that all seedlike structures which fail to germinate remain available 
for subsequent study.—Gro. H. SHULL. 
Color inheritance in Oxalis.—Several wild forms of Oxalis growing in 
nature at Tokyo, Japan, are found by Nowara” to constitute true breeding 
biotypes, and one wild form indicated its hybrid nature by producing 3 types 
of offspring in approximately a 1:2:1 ratio. The 4 homozygous biotypes 
were subjected to genetical analysis by controlled breeding. Reciprocal and 
double reciprocal combinations yielded only the same results as the single 
crosses, showing no differential effect of maternal and paternal germ cells. 
The 4 forms differed from each other in the presence and absence of a purple 
bar across the base of the petals forming an “eye,” and in the occurrence of 
several degrees of purple coloration in the leaves. The leaf and flower pig- 
mentation are associated, either by linkage or by the production of purple 
color in the leaves and the purple eye spot in the flowers by the same gene. 
As one of the true breeding forms has purple leaves and no eye spot, the rela- 
tion of these characteristics seems to be more logically referable to linkage. 
showing ratios approximating 1:2:1, and the F; behaviors are typical of Men- 
delian monohybrids. Three of NoHara’s forms are recognized by him as the 
taxonomic forms O. corniculata L., O. stricta L., and O. corniculata tropaeoloides 
(Schlachter) Makino, and the importance of a: eget studies in the solu- 
tion of taxonomic problems is made clear—Gro. H. SHULL 
Relation of leaves to climate.—BAILEY and Srynotr,” in continuing their 
study of the phylogeny of angiosperms, have begun an investigation of the 
9 Davis, B. M., A method of obtaining complete germination of seeds in Oeno- 
Proc. Nat. Acad. Sci. 
era 
pi 360-363. IgI5. 
% Nonara, S., Genetical studies on Oxalis. Jour. Coll. Agric. Imp. Univ. Tokyo 
6:165-182. pl. r. 1915. 
™ Bartey, I. W., and Srunnort, E. W., The — distribution of certain types 
of angiosperm leaves, Amer. Jour. Bot. 3:24-39. 1916. 
