352 WOOLFORD B. RAKER. 



granules during the early stages after division. This would 

 account for the fact that Blochmann records three instances where 

 he found two granules in the body of an animal. In one case he 

 records three as being present. 



The question arises as to the significance of this bit of nuclear 

 material sent into the cytoplasm at each division period. It 

 seems clearly demonstrated that it acts as the vehicle for the 

 transfer of the kinetic elements from the endosome to the cyto- 

 plasm. After the kinetic elements are freed it remains in close 

 connection with both the endosome and the blepharoplast for 

 sometime after division, in fact until the daughter cells are fully 

 reorganized. In this position we may conclude that it is homolo- 

 gous, both in structure and function, to the parabasal body of 

 parasitic flagellates. It seems to serve as a reserve of kinetic 

 energy until the newly developed motor apparatus is fully formed 

 and functioning normally. \Yith this function completed, does it 

 play any further role in the physiology of the cell? Only 

 conjecture can be made at present. It seems reasonable to 

 suppose however, that there is sufficient chromatin material in 

 the mass to bring about some sort of reorganization in the 

 cytoplasm of the body after each division. Thus the protoplasm 

 might be kept in a proper state of physiological differentiation so 

 as to make process of conjugation, autogamy or endomixis 

 unnecessary. The disappearance of the mass in the early stages 

 of each division is suggestive that in Euglena we find a mechanism 

 which functions as a sort of regulator of the division cycle. It is 

 possible that changes in this mass of chromatin, this kinetic 

 reserve, may be the stimulus which incites the division of the cell 

 with such striking regularity. Although it does not function as a 

 division center, yet it sets up a series of concatenated events which 

 result in the final production of two fully vigorous individuals 

 from the single parent cell. 



SUMMARY AND CONCLUSIONS. 



i. Mitosis in Euglena agilis is accomplished in a manner quite 

 similar to that described for higher plants and animals. Definite 

 chromosomes are formed, divide longitudinally and are dis- 

 tributed equally to the daughter cells. The chromosomes are 



