RIKER: CHONDRIOMES IN CHARA 143 
nucleolar substance contributes materially to the growth of the 
chromosomes. On the same subject Andrews (1) says, “it is 
probably utilized as food in the growth of chromatic masses.”’ 
Duggar (6) found an interesting connection between the chromatin 
content and the nucleolus, while Gardner (7) writes that the 
nucleolus is the important chromatic center, and that during 
division it becomes transformed into chromosomes. Wager (17) 
reports that during spireme formation the nucleolus becomes irreg- 
ular in shape, undergoes ameboid changes of form, and then disap- 
pears just before the formation of the chromosomes. This 
describes exactly the changes that were observed in the present 
study of the growing tips. 
In the metaphase and following stages the chromosomes 
remain entirely intact (Fic. 3). There is no sign of disintegration 
either of the central or outer portions. Hegner (9), working on 
the paedogenetic larvae of Miastor, finds that when the somatic 
cells become differentiated the middle portions of the chromosomes , 
break up into granules which divide and go to the poles, while 
the swollen ends are cast into the cytoplasm. Boveri (2) has 
shown in Ascaris that when the cells specialize portions of the 
chromosomes separate off and disintegrate. But nothing of this 
kind occurs in Chara. Here the chromosomes migrate to the 
poles in the usual manner, with the mantle fibers extending from 
the center of the chromosomes. In the anaphase sixteen chro- 
mosomes move to each pole, corroborating the count of sixteen to 
eighteen made by Strasburger (16). 
In the region of the median plate, after the chromosomes have 
been drawn away, a varying number (twelve to sixteen in C. 
fragilis and in C. verrucosa even more) of chromatic granules are 
found (Fic. 4), which are more or less globular in shape and which 
take the stains just as the chromosomes do. These granules, 
which are called prochondriomes hereafter, seem to lie between 
the spindle fibers and do not make connection with the mantle 
fibers. In size they vary from 0.6 » to 1.4 u in diameter, and the 
volume is calculated to be from 0.117 cu. » to1.47 cu. uw. As the 
chromosomes merge together in the telophase, these prochondriome 
granules may fuse so as to form eight or ten larger granules 
(Fic. 5), some of which may be up to 2.54 in diameter, or 4.9 
