EFFECTS PRODUCED BY CUTTING PARAMECIUM CELLS. 6l 



out ot individual forms in monsters of older growth. H< 

 the mass is watched from day to day, fairly complete cells make 

 their appearance only to be absorbed again in the general m. 

 This absorption i- .-analogous to that resulting from a \v<nmded 

 P(ininn'finni in which the cut failed to extend entirely through 

 the diameter ot the cell. In such cases the wound is closed and 

 the cut -urfaie- fuse within a short time. Experiment no. 25 

 d illustration of the appearance and disappear- 

 ance ot individuals Inun the common proiopla-ni'V ma of -uch 

 a mon-ter. tin- bud- Jway- growing into a -etnblance .it lea-t 

 of the typical I'nr<. m. 



\ orm in Paramc> iuni, therefore, i- a per-i-teiit characteri-tic, 

 apparently independent of movement, and connected in -ome 

 \\.iv \\iih I In- phy-ical make-up of tin- protoplasm. 



Regeneration oi tli .i-m which occur- in a -mall percent. 



- \ar\ing in ditlereiit races, i- probably due \ a perfectly 



balanced plu-i'-lo:.!. il condition of the cell. This conclusion is 



dedmed ironi the tact obiained in main experiment-, that a 

 coni|>arati\el\ in-i^niln ant i lit \\ -hereby only an e\uvmit\ of a 

 I'uriinn-i'inni i- r<-ni"\ed. ha- a profound effect upon the further 



activities of the eel!. Kvunple- are J\ell in eXpelimelll- of 



Table I. and of Table IV.. \\ here "in- or the other end of tin- i ell 

 \\a- remo\ed. lii the inajontN ..I '-iilnal fragment 



died \\ilhin a -hoiM period; in a te\\ cases tin- le-idual tia^im-nt 



di\ided asymmetrically, ^i\in^ ri-e to on- normal Paramecium 



\\hich coiitinui-d to |j\e and to multiply normally, ami an ab- 

 normal cell \\hich - i died: in a leu :n, the fragment 



neiated either i >v -ooii alter di\ i-ioii. 



l! tlii- phenomenon could be explained \ve -Innild be wi-11 on 

 the \\a\- to an e\| ilan.it ion of that ^ho-t- train of processes u hich 



we designate vitality. I k of a balancing of pr , or 



of a -table and un-table equilibrium. ln>\\e\-er, i- no explanation 

 of what take- place. N.me recent ob-er\ ei> ha\e imdert.iken 

 the ta-k of explaining cell ph\ siology, iiu hiding di\ i-ion. through 

 the \ar\ingratioof nuclear ma-- to c\ topla-mic ma . Balbiani 

 bi'lie\ed that nion-ter.- are due to some slight injury to the maCTO- 

 nucleus in cutting, and made tin- !i/atioii thai tlu-\- are 



"alway- indi\ idual- mutilated in the anterior part who-e de- 



