54 i.ARV X. CALKINS. 



No. 6 (Table III.) was a similar monster, hut was derived from 

 a normal vegetative cell cut in zone III. After three days the 

 fragment had attempted to divide; a constriction was piv-un 

 but the posterior cell was only a swelling with a mouth opening 

 and no peristome (Plate III., Fig. 19, a, b, c). 



In the remaining eleven cases of monster formation many 

 degrees of malformation resulted from the operation. Of these 

 the least monstrous was no. 23 (Table III.). The original cell 

 was cut as shown in Fig. 13, Plate II. There was no sign of 

 regeneration during the next three days but the cell grew larger 

 and finally attempted to divide (Fig. 13, b, c). One of the cells 

 was normal in shape and size; the other, posterior, was smaller 

 and truncated. The two remained attached for a period of 

 three days swimming about actively, bending and twisting with 

 the various cilia in action, until they finally died, undivided, nine 

 days after the operation. The nuclear apparatus was not deter- 

 mined. In this case two complete peristomes and mouths were 

 developed and the cells were attached by only a delicate strand 

 of protoplasm. The general result was similar to that of experi- 

 ment no. 7 (Table IV.) in which the daughter cells remained 

 attached for 24 hours and finally separated, dying shortly after 

 the separation (see page 52). 



Other monsters formed without division of the cut cell were 

 n os. 35, 39, 40, 51 and 68 of Table II., and nos. n and 41 of 

 Table III. Nos. 35 and 39 were killed after 4 and 5 days respec- 

 tively, while nos. 68, n and 41 died in from 4 to 8 days. The 

 other two, nos. 40 and 51, lived for 20 and 17 days respectively, 

 and developed into relatively huge protoplasmic masses. 



The remaining three monsters, nos. 22 and 25 of Table II., and 

 no. 17 of Table III., all came from an original form that divided 

 after the operation into one normal and one abnormal cell, the 

 monster in all cases coming from the abnormal cell. 



The history of only the most interesting of these monster- 

 need be given, all matters of importance in the other cases being 

 included in the history of these. 



The simplest case is no. 51 which lived, after cutting, for 17 

 days undergoing two attempts to divide in that time. The cell 

 was cut as shown in Fig. 14, Plate II., in /one II., and the- frag- 



