Vol. 44 No. WD 
BULLETIN 
OF THE 
TORREY BOTANICAL CLUB 
a ee 
DECEMBER, 1917 
The development of the embryo-sac and of the embryo in Phaseolus 
vulgaris 
MaseEL Mary BROWN 
(WITH PLATES 25 and 26) 
INTRODUCTION 
So far as I have been able to find, the only previously pub- 
lished description of the embryo-sac or embryo of Phaseolus is by 
Guignard (1881), who studied forty species of Leguminosae, 
among them Phaseolus multiflorus. In this species he found that 
an axial row of but three macrospores is formed. The innermost 
cell of this row by three successive nuclear divisions forms the 
embryo-sac, which is typical in every respect; the antipodals are 
ephemeral. The first division of the egg is transverse, and occurs 
at the same time that the primary endosperm nucleus divides. 
A pro-embryo of three cells is formed, the terminal one of which 
develops into the embryo; the other cells form the suspensor. 
Divisions follow until an embryo is formed at the apex of a fila- 
mentous suspensor, which is two cells in thickness and whose 
basal cells are conspicuously swollen. 
In the present study buds, pistils, and developing fruits were 
obtained from the following varieties of Phaseolus vulgaris: ‘‘ David 
Kidney,” “Longfellow,” “Pole,” and “Kidney Wax,” plants of 
which were grown in the greenhouse during the fall and winter 
of 1914-15 and 1915-16, and ““Wardwell’s Wax,” grown in the 
[The Butterin for November (44: 501-534 pl. 24) was issued November 20, 1917] 
