

1901] THE LIFE HISTORY OF ERYTHRONIUM 379 
becomes free and continues to orient itself and contract until 
the looped mother skein is formed. There is a continuous 
shortening and thickening and often twisting up of the entire 
spirem, but the contraction is not one-sided, and it does not 
appear to have any special relation to the nucleolus. 
THE SECOND AND SUBSEQUENT DIVISIONS. 
The division of the reduction nucleus gives rise to the first 
two cells of the gametophyte. The daughter nuclei go into a 
resting stage and form a network from which a new spirem is 
developed (figs. 67-63). The network at first shows granules 
which are visible in a single chain in the spirem (ig. 66), but they 
are not visible after the mother star is formed (figs. 68, 69, 70). 
The chromosomes are distinctly V- and U-shaped, and the daugh- 
ter chromosomes are formed in the ordinary way by longitudinal 
splitting (figs. 69, 70). This is a normal quantitative karyo- 
kinesis, therefore, which is quite similar to the sporophytic quan- 
titative karyokinesis except that there are only half the number 
of chromosomes formed by the transverse breaking of the spirem. 
Several countings indicate about twelve chromosomes in the 
daughter star. In one case the chromosomes were all distinct 
and plainly twelve in number. 
The spindle in fig. 68 has been sectioned, and this may 
account for the lack of poles. The relation of the large vacuoles 
to the position of the poles of the incipient spindle should also 
be noted (figs. 65-67). There are often remarkable radiations 
around the mother nucleus. These have nothing to do directly 
with the formation of the spindle, however, and are the radia- 
tions normally present at this stage in both plant and animal 
karyokinesis. In some cases it appears that they may have 
their origin at the dome-shaped caps of the spindles (figs. 63, 
64). There are also numerous strands of the central spindle 
left between the daughter nuclei of the first division, and it is 
probable that some of the radiations around the daughter skeins 
may also be left and be preserved to the beginning of the fol- 
lowing division. The third division which gives rise to the 
