STUDIES ON THE DYNAMICS OF MOBPHOGENESIS 



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TABLE 5 

 From several series. Worms 12 — 15 mm. in length, in good condition. 



involved in the formation of the head in both cases. Moreover, 

 as series 182 shows, the anterior quarter of the piece, when iso- 

 lated from the other parts, produces no normal wholes at all. 



In table 5 the pharyngeal region alone is included. Here, as 

 in table 4 a number of series are combined. The results of the 

 regulation of the pharyngeal region when isolated as a whole and 

 when separated into equal pieces are compared. 



This table like the others, shows the marked decrease in the 

 capacity for the formation of wholes with the decreasing size of 

 the pieces. 



The data presented in the above tables are all from the exper- 

 iments of later years. In addition to these my notes contain 

 the records of several hundred individual worms which were cut 

 into pieces from two to twenty-four in number. It was the study 

 of these individuals that led me to the conclusions for which the 

 later series of experiments have merely given a more general 

 expression. It is impossible, however, to combine these individ- 

 ual records into larger series, for worms of different size were 

 used in those experiments, the pieces were often of different 

 length so that levels of section in different worms do not corre- 



