144 RIKER: CHONDRIOMES IN CHARA 
cu. » in estimated volume. The chromosomes are 0.7 yw in thick- 
ness and 5-6 win length, which gives a calculated volume of 2.37 
cu. uw. It is estimated that the amount of chromatic material left 
behind in some cases may be equivalent to six or eight chromo- 
somes, or almost half the amount of chromatin that makes up 
one of the daughter nuclei. 
At the poles the chromosomes do not fuse directly into the 
daughter nucleus, but groups of them form pre-nuclear masses 
(Fig. 5), each of which contains a deeply stained chromatic spot 
resembling a nucleolus surrounded by a clear area. Then these 
pre-nuclear masses rapidly fuse into one large daughter nucleus 
(FIGs. 5-7). 
The prochondriomes still persist on the median plate during 
the formation of the daughter nuclei. They do not disintegrate 
but soon migrate into the cytoplasm, where they divide repeatedly 
by fission to form bodies of different sizes. These are the granu- 
lations or chondriomes described by Mirande. Thus it appears 
that the greater number, at least, of the bodies staining as 
chondriomes in Chara may be nuclear in nature, and are, in 
part, expelled by the nucleus itself. On the other hand, this idea 
is exactly contrary to that of Guilliermond and Mottier, who say 
that chondriomes in general arise only from other chondriomes. 
Meves and Mottier suggest that, because chondriomes are such 
definite organs of the cell, they may be the bearers of certain 
hereditary qualities. 
The leaves of Chara are formed by successive divisions of the 
tip cell. This tip cell seems to contain more of the chondriomes 
than any of the other cells. In fact the amount of chondriome 
material in the tip cells of the young leaves is approximately equal 
in many cases to the chondriome material in all cells below it. 
There is thus a progressive accumulation of chondriome material 
in the tip leaf cell during the successive divisions. 
It is impossible actually to trace these prochondriomes to their 
position on the central plate, for they cannot be definitely picked 
out among the tangle of chromosomes in the metaphase. No 
more can their exact origin be seen. It would seem that they 
may be either (a) delayed chromosomes, (6) entire chromosomes 
which never go to the poles, (c) portions of chromosomes which 
