284 Allen . — The Early Slaves of Spindle- Formation 
Passiflora and Lavatera , and in the second division in 
Magnolia and Liriodendron (Andrews). 
In a type of spindle-formation first described by Rosen 
(’95) in the root-tip of Hyacinthus , a thin hyaline extra- 
nuclear zone is seen, whose material becomes aggregated on 
two opposite sides of the nucleus. Within each cap so 
formed, fibres appear and grow in length, attaching them- 
selves at one end to the nuclear membrane and finally 
converging at the other end to a common point. Then the 
membrane disappears and the spindle is completed. Nemec 
(’97, ’98#, ’98$, ’99#, ’99 £,’99 c) describes spindle-formation from 
similar extra-nuclear caps in root-tips and other vegetative 
tissues of Allium , Hemerocallis , Solanum , and a long list of 
plants. He finds that in general the spindles in vegetative 
cells are from the start bipolar, while those in reproductive 
cells are originally multipolar. Hof (’98) finds similar polar 
caps in the root-tips of Ephedra and Vicia. In the former 
case, the spindle is originally bipolar, in the latter monaxially 
multipolar, becoming bipolar. Schaffner (’98, ’ 01 ) describes 
spindles arising from similar extra-nuclear caps in the root- 
tips of Allium and Erythronium ; and Fullmer (’98, ’99) finds 
the same thing in pine seedlings, and also in pollen-mother- 
cells of Hemerocallis , where, however, he describes also an 
early radial stage. Miss McComb (’00) relates a similar 
history in the root-tips of Allium , Vicia and Erythronium , 
except that instead of the early hyaline layer she finds a 
kinoplasmic weft or felt surrounding the nucleus ; and it is 
this felt that becomes aggregated into the polar caps. 
Strasburger (’ 00 , p. 118 ) has pointed out that in the vege- 
tative divisions described by N£mec the spindle primordium 
(‘ Anlage ’) at each end of the nucleus is at first composed of 
separate spindle-bundles, not converging to a common point. 
He proposes for this condition the term ‘ multipolar diarch,’ as 
distinguished from the ‘ multipolar polyarch ’ form common 
to reproductive cells, in which poles arise on all sides of the 
nucleus. He finds, in the root-tips of Ephedra and Vicia , 
a finely fibrous extra-nuclear layer which becomes aggregated 
