REGENERATION IN PARAMECIUM CAUDATUM. 



159 



No. i. This monster arose from one of the fragments in 

 Table I. where the anterior end of the cell was removed (Fig. 3). 

 At the end of twenty-four hours the fragment (B) appeared 

 active but showed no sign of fission; the cut end was slightly 

 rounded. Before the end of forty-eight hours division took 

 place in the original plane producing a small individual (C) and 

 a large one (D}. On the following day C began to divide. 

 During the next night fission was completed and another small 

 () and large (F) cell formed. On the fourth day E had increased 

 in size, and showed signs of division. On the fifth day it had 

 formed a chain of three cells (G),the most posterior of which 

 formed a normal individual. The chain continued to throw off 



N 



\ 



N 



FIG. 4. Diagram showing the formation of five normal races and one monster. 



normal cells posteriorly until finally after a period of growth a 

 mass was left which separated into two parts (L and M). These 

 when killed and stained were found to possess several mouths, 

 but neither piece contained more than one nucleus. 



No. 2. The second monster arose in the same way from a 

 small anterior cell produced by the division of a fragment in the 

 original plane. In this case a chain of five parts (Fig. 4) formed 



