* 
1897 } LIFE HISTORY OF LILIUM PHILADELPHICUM 445 
division they are again collected into the daughter nuclei, where 
| by repeated fusions they form the large nucleoli of the mature 
daughter nuclei. 
Cytoplasmic adiations and spindle threads.—The tangential 
threads which I observed in the early stages of the development 
of the macrospore nucleus are no doubt the same as those 
recently described by Mottier and others as being the begin- 
nings of the achromatic spindle. They do not converge to defi- 
nite points, however, but pass almost in straight lines across the 
cell from one wall to the other, the greater number appearing 
to pass in a direction longitudinal to the long axis of the grow- 
ing macrospore. From their varying direction it follows that 
ec. there must be numerous points of intersection, but it does not 
appear that any number intersect at a given point. At a later 
stage, in very fine sections, these radiations do not appear at all, 
but a new set of cytoplasmic threads appear diverging in every 
direction, and at right angles to the nuclear surface. These 
radiations are the same as those figured so beautifully by 
Guignard. Whether these diverging radiations represent the 
Same structures as the earlier tangential threads or not I could 
not determine. They were never seen to converge to definite 
points, but I can easily imagine how in a contracted condition 
of the cytoplasm they might give such an appearance. My 
belief is that the real purpose of these radiations is to carry out 
_ the micronucleoli into the cytoplasm. They appear just when 
the micronucleoli begin to migrate, and it is difficult to imagine 
how the nucleoli could pass outward unless carried by streams 
_ of cytoplasm. 
___ The formation of the spindle was not folleawed, but in the 
‘Mother star stage the spindle is always bipolar and ends in a 
: definite point. No appearance of a multipolar spindle was ever 
Observed, unless in cases where the spindle had been cut or torn 
_ Even granting that the spindle is formed as Farmer states, 
there may still be two unseen centrospheres toward which all 
the small poles of the multipolar spindles are attracted. It is 
: = gaceivable to the writer how a definite sie pate should 
