Vol. 49 | : No. 3 
BULLETIN 
OF THE 
TORREY BOTANICAL CLUB 
MARCH, 1922 
Quadripartition by furrowing in Sisyrinchium 
CLIFFORD H. Farr 
(WITH PLATE 2) 
Since the publication of the author’s paper (5) on Magnolia 
there have appeared a few contributions to the subject of the 
quadripartition of pollen-mother-cells by furrowing. In 1918 
Tackholm and Séderberg (24) presented an interesting discovery 
of the occurrence of quadripartition and bipartition respectively 
in two species of Aristolochia, a genus of Dicotyledons; Aristo- 
lochia fimbriata was found to have successive bipartition, just 
as Samuelson (19) had reported in this genus, but Aristolochia 
Sipho was found to have quadripartition of the pollen-mother- 
cells after the homoeotypic mitosis. It is stated that there is 
a slight thickening of the spindle fibers after the heterotypic 
division in the latter species, but no figures of quadripartition 
are shown in this paper. In Vinca rosea the authors conclude 
that quadripartition must occur because of the tetrahedral 
arrangement of the microspores within the mother wall. It 
will be remembered that Frye and Blodgett in 1905 (8) found 
successive bipartition in the sister genus Apocynum, and the 
microspores here are sometimes arranged tetrahedrally. The 
authors (24) state that after the homoeotypic division in Aris- 
tolochia Sipho walls are laid down as fine plates on the equator 
of the spindle, and that in Albizzia lophanta, a Dicotyledon, 
and Dioscorea quinquefolia, a Monocotyledon, quadripartition 
[The Buttetin for February (49: 31-50) was issued April 4, 1922.] 
2 i 
