1914] BRIEFER ARTICLES 531 
spicata should be included surely does not indicate that he regarded it as 
more representative of his Danthonia than decumbens, since his generic 
description provides for the latter (“awn sometimes long, sometimes 
rudimentary”’). 
he adoption of Avena spicata L. as the type, therefore, is seen to be 
purely arbitrary, since such action is based on the present interpretation 
of the genus.—AVEN NELSON and J. Francis MACBRIDE. 
MATURATION IN VICIA 
(PRELIMINARY NOTE) 
The following preliminary note summarizes the results so far obtained 
in a study which has been temporarily interrupted. Although many 
details remain to be worked out, the following points seem clear. 
In the somatic cells of Vicia Faba there are twelve chromosomes; 
two of them are about twice as long as the other ten. How this size 
difference arose is not known, but there is some reason to believe that 
each long chromosome may have been formed originally by the coherence 
of two ordinary ones. 
In the early prophases of the heterotypic mitosis in the pollen 
mother cells, the chromosomes take the form of long slender threads 
(leptonema), which become paired side by side (zygonema). These 
double threads shorten and thicken (pachynema), the association of the 
two members of each pair becoming very intimate. The nature of this 
union has yet to be determined. Synizesis occurs during these prophase 
stages as a natural phenomenon. 
At diakinesis there are six gemini; one of them is about twice as 
large as the other five, showing that the two large chromosomes seen in 
the somatic cells have paired with each other. At the first maturation 
division the members of each pair pass to opposite poles, bringing about 
the reduction. In the second, or homeotypic, mitosis all the chromo- 
somes divide longitudinally, so that each microspore receives six chromo- 
somes, five short and one long. 
The megaspore mother cell has not been examined, but in the light 
of the above data on somatic and pollen cells it seems probable that 
similar phenomena occur in the maturation of the megaspore. 
The results here recorded are of special interest in that they furnish 
further evidence in favor of the theory that the two chromosomes which 
pair and separate at the first maturation division come one from each 
parent, and are in some sense homologous.—LEsTER W. SHARP, Uni- 
versity of Chicago. 
