Ms 
‘gid é 
1899] SPORE-MOTHER-CELL OF ANTHOCEROS 99 
structure. The delicate threads lie all around the nucleus, but 
they accumulate conspicuously at the pointed projections (jigs. 
12, 13). 
At this time one is apt to find the linin network contracted 
away from the nuclear membrane and gathered in the form of a 
confused tangle in the central region somewhere near the 
nucleolus (fig. 73). The chromatic material becomes more 
prominent and from the ill-defined mass in the interior there 
emerge four deeply staining chromosomes (figs. 12,74). When 
the chromosomes are fully differentiated one may expect to find 
one or two of the angles of the nucleus more prominent than 
the others, and the fibrils around them taking on the appearance 
of spindle fibers (figs. 73, 74). The process of spindle differ- 
entiation is a gradual one, and only in the later stages is it pos- 
sible to feel sure of the direction that the axis will assume. I, 
is seldom that the two poles appear from the beginning so nearly 
°pposite one another as to have a common axis. It is more 
usual for the spindle to be somewhat bent at first, as is shown in 
fg. 14. However, ultimately the two poles arrange themselves 
‘o form a symmetrical spindle of the form illustrated by figs. 75, 
16, 17, 78. 
Me fully developed spindle has an interesting structure, with 
several clearly marked features well shown by fig. 8. The poles 
. oe periiaps slightly convex ; they are never pointed. 
Brest es are conspicuous around the nuclear plate ( figs. 16- 
), but what relation these bear to the chromosomes could not 
be determined. 
. — : the condition reported by Farmer (94 and ’05) for 
Poskiake the Hepaticae, notably Pellia, Pallavicinia, and 
Whether oo it became a very important problem to determine 
the — centrospheres were ever present at the poles of 
care for te The writer searched his preparations with great 
do not ae structures, but came to the conclusion that es 
the Spindle ¢ ey Anthoceros, Sometimes the cytoplasm aroun 
shown in fi Ontains large deeply staining granules, such as are 
© 47, and these may occupy positions near the ends 
