336 WOOLFORD B. BAKER. 



become elongated and thread-like. In the meantime the body 

 of the chromatophore loses its definite outline, becomes more 

 rounded and apparently increases in size. The individuality of 

 the pyrenoid becomes less distinct, until the later stages show the 

 chromatophore as more less homogeneous with a slightly denser 

 central region. This central region increases in size, elongates, 

 becomes constricted in the center and forms two regions from 

 which the pyrenoids seem to form in the reorganization period of 

 the cell. This division of the chromatophores is not synchronous 

 with the division of the nucleus and the cell, since in many cases 

 the number of such bodies is seen to be halved in the division 

 process, and division of each occurs later. In almost all instances 

 however, the internal changes in the pyrenoid accompany the 

 changes in mitosis. It is planned to make a detailed study of the 

 behavior of the chromatophores and pyrenoids, with special 

 reference to their relation to the mitochondria of the cell, the 

 subject of a later paper. 



Behavior of the Flagellum and History of the Kinetic Elements. 



In the early prophase the external flagellum seems to become 

 more viscous and sticky so as to adhere readily to external objects 

 or to the oral region of the animal. Many stained specimens 

 show the flagellum much shortened and thickened at this stage, 

 with abundance of foreign particles adhering to it. Frequently 

 the end adheres to the body near the cytostome and with the 

 foreign particles attached obscures the opening into the gullet. 

 This evidence of dissolution progresses inward, eventually 

 involving the two branches in the reservoir, as well as the 

 blepharoplast and basal granule on the lower border. In a few 

 instances remains of the old flagellum have been observed in the 

 late metaphase (Fig. 7). As a rule however, the flagellum seems 

 to have been absorbed or sloughed off at a much earlier stage. 

 Berliner has described a somewhat similar degeneration in 

 Copromonas major. Other observers describe the disappearance 

 of the motor apparatus during division; Wallengren (1905); 

 Dobell (1908); Hartman and Chagas (1910). In other instances 

 however, the flagella are said to persist for one daughter cell and 

 new ones are developed in the other: Cutler (1919); Jameson 

 (1914); Whitmore (1911); Awerinzew (1907). 



