GARY N. CALKINS. 



individuals entirely unaffected by the operation. The abnormal 

 cell in some cases, divides again asymmetrically and forms 

 another normal cell and an abnormal cell; in other cases the 

 second division is abortive and monsters are formed; in a fra- 

 cases it continues to divide with a gradually decreasing abnormal- 

 ity until normal forms are regained; in many cases, finally, it 

 dies without further division. 



7. The monsters represent as many individuals as there are 

 mouths. In one monster as many as fourteen mouths were 

 present at one time. There is a well-marked tendency of the 

 protoplasm to assume the form of a normal Paramecium about 

 each of the mouths, and such individuals bud out of the proto- 

 plasmic mass, remain for several hours, and may be absorbed 

 again into it. 



8. Free cells, complete in all respects, may be given off from 

 the protoplasm of a monster. These may live for days and may 

 even divide, but vitality is weak and they invariably die. 



9. Cell division and cell regeneration are entirely independent 

 phenomena. A fragment divides without regenerating and the 

 abnormal product of this division may divide again without 

 regenerating. In other cases the fragment divides asymmetrically 

 and the resulting abnormal cell regenerates before the following 

 division. The cell need not regenerate to divide, and may or 

 may not regenerate before dividing. 



10. The Paramecium cell acts as a unit; cytoplasm and nucleus 

 are equally important, a small loss at either extremity is usually 

 enough to throw the physiological mechanism out of gear and 

 lead to death, to asymmetrical division, or to monster formation. 



1 1 . The phenomena resulting from cutting Paramecium cannot 

 be explained on the Kernplasmarelation theory of the Munich 

 5( hool. Mass of nucleus in relation to mass of protoplasm is 

 only a morphological index of the physiological (chemical, 

 electrical) activity of the cell an effect and not a cause of the 

 \ .moiis vital reactions. 



12. Regeneration of a cut cell in race> with a limited po\\ ei ot 

 regeneration, is more often observed in cells that have recently 

 conjugated, or in cells that were cut while in conjugation, than 

 in ordinary \ei;etaiive cells. 



