258 University of California Publications. [Botany 



Chromosomes. 



Kohl. This author has a definite number of chromosomes in 

 each species which, judging from his illustrations in tables i and 

 k, separate simultaneously. The division is crosswise and in the 

 middle (p. 173). 



Phillips. An indefinite number of chromosomes is present, 

 in some cases many fine ones, and in other cases about two coarse 

 ones. In either case they divide crosswise in the middle simulta- 

 neously (p. 297). 



Olive. A definite number of chromosomes is present in each 

 species. These are divided in the same plane as the spireme in 

 which they are enclosed or held fast, the division beginning at 

 the ends of the "segmented spireme" in Gloeocapsa, and pro- 

 gressing toward the center, and beginning around the margin of 

 the disc in the "convoluted spireme" of the short-celled form, 

 progressing toward the center of the disc dividing the granules 

 hit or miss as they are reached (p. 36). 



Spindle. 



Kohl. "Innerhalb der eingeschnurten Partie des Kernes 

 konnte ich bei geeigneter Fixierung und Farbung deutlich Spin- 

 delfasern in wechselnder Zahl erkennen" (p. 173). 



Phillips. An "open" spindle is formed by the segments of 

 the spireme (pp. 296, 297). 



Olive. The kinoplasmic achromatic portion of the central 

 body constitutes a "spindle," the shape of which varies with the 

 shape of the cell. It consists of two parts, one extending be- 

 tween the dividing chromosomes and the other attached to the 

 chromosomes and extending to the cross-walls of the cell (p. 36). 



Nuclear Membrane. 



Kohl and Phillips find no nuclear membrane, but Olive finds 

 a delicate one in spores. 



Granules. 



Two kinds of granules have been observed by each of these 



writers, viz., the "slime globules" and "cyanophycin granules." 



From the doubtful manner in which some of these conclusions 



