1921] VAMANOUCHI—CORATIINA gl 
of reproductive organs (antheridia, carpogonia, and tetraspores) 
are produced in conceptacles on three different individuals. 
Nuclear division in vegetative cells 
Nuclear division is very common among any of the vegetative 
cells, but is most conspicuous among the actively growing (disk) 
cells at the ends of the branches. The cell structure varies more 
or less according to the position of the cell, but as a rule the nucleus 
occupies the central portion of the cell. One or sometimes two 
large vacuoles are present, and also many chromatophores. The 
cytoplasm seems to be distinctly alveolar in structure. The 
nucleus in the resting condition contains one and sometimes three 
or four irregular nucleoli. The chromatin material, during the 
resting condition of the nucleus, consists of small granules scattered 
throughout the karyolymph. Upon approaching the period of 
nuclear division, the nucleus slightly enlarges, and the chromatin, 
which up to this time was in the form of granules, increases in 
amount and finally becomes organized into a definite number of 
chromosomes. The male and female individuals possess twenty- 
four chromosomes, while the tetrasporic individuals have forty- 
eight. The contents of the nucleolus gradually become decreased 
with the formation of the chromosomes, and when the chromo- 
somes have arranged themselves in an equatorial plate, the nucleolus 
has completely disappeared. 
In the prophase a small, granular, centrosome-like body makes 
its appearance at each of the two poles of the nucleus in the cyto- 
plasm near the nuclear membrane. Within the nucleus spindle 
fibers are soon formed, originating from the centrosome-like body. 
The alveoli of the cytoplasm immediately surrounding this 
- centrosome-like body form branched astral rays. In later prophase 
the centrosome-like body becomes enlarged, and thus the centro- 
sphere is produced. 
In the metaphase the chrémosomes divide, and when the two 
groups of daughter chromosomes reach the opposite poles, the 
daughter nuclei are soon formed. Up to and including the forma- 
tion of the daughter nuclei, the centrosome-like body retains its 
characteristic form. With further growth of the daughter nuclei, 
