86 BOTANICAL GAZETTE [ AUGUST 
unites with another bundle or continues as a single fiber to the 
pole. The arrangement into bundles seems to be produced } 
partly, at. least, by the fibers being crowded into the small spaces 
between the chromosomes. This explanation is rendered more 
probable by the fact that, as Strasburger has pointed out, the 
arrangement into bundles is much more evident at the equator 
than in the polar regions of the spindle (of. ciz., p. 183), 2.é., the 
fibers forming a single strand often seem to diverge beyond the 
equator. Some of my preparations show that this divergence 
reaches to the ends of the strand (fig. 23), so that such strands 
are most compact where they are adjacent to the chromosomés. 
The appearance of single fibers crossing obliquely from one 
bundle to another, together with the fact that such fibers often 
cross and recross each other, was taken by Belajeff as evidence 
that the fibers are drawn out portions of a protoplasmic net 
work. Guignard’s observation that the number of connecting 
fibers is equal to the number of chromosomes may be explained 
by the hypothesis that the fibers are collected into larger strands 
in the spaces between the chromosomes. Guignard, as previously | | 
stated, described such fibers as secondary fibers formed by Ls 
lateral fusion of previously existing smaller primary fibers. He 
did not, however, distinguish any other than the connecting 
fibers. Strasburger later showed that there are other fibers 
extending from the poles to the chromosomes. These are 
mantle fibers. They have been so clearly demonstrated recent 
by Osterhout, Mottier, Nemec, and others, that I need give 
detailed description of them in this connection. Suffice to say’ 
I find no apparent difference in structure between them and the a 
connecting fibers. : 
The third system of fibers to which I have referred may be 
described briefly as including those which extend from the poles 
into the cytoplasm. They are much more abundant in the lat 
than in the onion; hence I shall first describe them as the 
appear in the former. They seem to have the same structure 
the connecting or mantle fibers. Strasburger has figured them 
in the larch as radially arranged granules, while the conne¢ 
