STUDIES IN KARYOKINESIS. 
BY JAMES ELLIS GOW. 
The work whose results are here presented has been done at 
various times and places. The investigation of Trillium was 
undertaken at Blairstown during the fall and winter of 1905, and 
was carried on in the Botanical laboratory of the Blair Academy. 
Indian Corn and Arisaema were studied during 1901 and 1902 at 
the State University of Iowa, under the personal direction of Prof. 
T. H. Macbride, to whom are due thanks for the first suggestion 
leading to the undertaking, and for continued advice and assist- 
ance. 
TRILLIUM SESSILE L. 
Flower buds of Trillium sessile , cut in March, were killed and 
fixed in one per cent acetic acid and stained in Delafield’s Haema- 
toxylin. It was found that the sporogenous tissue was fully de- 
veloped, the cells were in active division, and in some of the 
flowers the mother cells were breaking up into tetrads. 
The earliest stage of division discoverable was that illustrated 
in Fig. 1. Careful search failed to reveal anything resembling the 
continuous spireme as figured by Schaffner in the onion and found 
by me in Indian corn. The chromatin first appears as a series of 
disconnected fragments in the surface of the nucleus. There is no 
evidence that it ever forms a continuous ribbon. The irregularity 
of arrangement does not indicate the presence of a ribbon com- 
posed of alternate areas of chromatin and linin, but rather a num- 
ber of totally disconnected chromosomes. From the first the chro- 
mosomes show a tendency to split longitudinally, the process be- 
ginning at one end, and never, so far as observed, at both ends 
simultaneously. The normal number of chromosomes is twelve, 
which becomes six in the reduction division. 
In the monaster, or mother star stage, the grouping of chromo- 
somes about the spindle is very irregular. In many cases the 
chromosomes appear to adhere to the spindle by the middle, or by 
a point near the end, although this is difficult to determine. At all 
events, when the separation of the two halves begins, it does not 
proceed from the middle, but from one end. In the daughter star 
stage of division the chromosomes show considerable irregularity, 
with a general disposition to change their shape and assume a 
-curved position as they approach the poles of the spindle. There is 
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