EFFECTS PRODUCED BY CUTTING PARAMECIUM CELLS. 53 



effect can be produced by such a minor mutilation and it suggests 

 the possibility pointed out by McClendon, of different electrical 

 states at different portions of the cell. 



A. tin. in no. 12 the fragment lived for five days without 

 division r regeneration and finally died. Peristome and mouth 

 were normal but the loss of the posterior end appeared to be 

 fatal. 



V>. 15 divided 24 hours after cutting forming one truncated 



iterior cell and a normal anterior cell. The physiological 

 bal.tnc,-, ho\\,-\ ,-r, was again disturb, d for both cell- died on the 

 follou in- day. 



No. i') ua- n>! -o seriously affected by the operation; the cut 

 fragment i^rrv. I.<uer each day up to ~2 hours when it divided 

 into one truncat.-d and one normal cell, the latter dividing a^ain on 

 the fifth day, the former dividing on the -ixth. forming practically 

 normal i ell-. 



<M the form- that regenerated nos. i ami 3) both were con- 

 jugating uhcn cut. In no. I both cell- \\eiv cut. >eparuion 

 lo||,, \\.-.l normally ami each cell had tilled out normally by the 

 toll,, \\im; day. 1 'lie. however, gt>\\ more and more feeble until 



it imalU dii-il. The other was entirely normal and was used for 



experiment Ji. In no. 3 onl\' one cell of the pair was CUt, \\\>- 

 other reiiiaininv: uninjured. Alt,r 24 hour- both were per 

 in lorin. ahli"ii^li one was perceptibly -mailer than the other. 

 I '. :h died on the -ixih clay. 



Monger . Of the I^ mon.-ter- only one re-tilted from a 



specimen that \\a- cut during di\ i-i<>n. all of the ot her- came It "in 

 tia^niellt- ot Vegetative cell-. !.!>.'ht of tin- thirteen Uel'e cell- 

 that had been cut in /ne II., the other live in /one III. In all 

 cases the po\\er to divide \\a- limited to the nncleii-, the cell 



boi I \ appareniK beiir^ incapable of division. 



In no. i, I'.iM, II. the ''II ua- dividiiiL; \\lu-n cut through 



the anterior half of the posterior cell (Plate III., Fig. [8). The 



ti. lament li\ed for three <la\- \\heii it \\.i- killed for nuclear 

 -inn inre-. T\\ ent> -four hour- alter cutting the po-terior part 

 developed a n r \\ peri-toiiu 1 and mouth on the cut -urface. but 

 the original div i-i<>n ua- never ("inpleted. \\ hen killed the i rll 

 had one large nuclei!- which had grown during the three d. 

 The other nucleti- had apparenilx been cut away. 



