342 SERGIUS MORGULIS 



days, and 77.26 per cent at thirty-five days after operation. 

 Furthermore, an examination of column six shows that the worms 

 gradually lost in weight, though not as much as in the previous 

 experiments. The greatest loss was sustained in the earliest stages 

 (11.2 per cent) ; at the closing of the experiment the worms weighed 

 30.6 per cent less than the control specimens. The quantity of 

 dry substance diminishes somewhat during the first half of the 

 experimental period, but remains very nearly constant during the 

 remaining stages. The quantity of water, on the other hand, is 

 lost at a slower rate, and at .about the time when the highest 

 per cent of water content is reached it does not decrease at all. In 

 later stages, when the dry substance remains practically constant 

 in quantity, the amount of water diminishes somewhat more 

 rapidly. These points can be best appreciated from the graphic 

 representation (fig. 7) of the data given in table 4. 



Considering in their entirety the results of the experiments 

 described above and directing our attention to the essential 

 points in the diagramatic representations of the data, we find 

 that soon after the operation the per cent of water rapidly rises, 

 the maximum usually being reached between the fifth and the 

 fifteenth days after operation. The lack of uniformity in the time 

 at which the maximum per cent of water is observed in the several 

 cases is* partly due to reasons indicated in an earlier section of this 

 paper, but partly to the fact that the water content was deter- 

 mined not daily but at intervals of several days. The period of a 

 high percentage of water in the regenerating animals is of short 

 duration, and is followed by a gradual decline in the water con- 

 tent. In short, the changes in the per cent of water during regen- 

 eration are expressed by a curve similar to the curve of the rate 

 of regeneration itself, as may be best seen by comparing with 

 one another figs. 3 to 7. The interesting fact is that the period of 

 the highest regenerative rate coincides with that of the highest 

 per centage of water, but whether these phenomena are simply 

 concomitant or whether they stand to each other in the relation of 

 cause and effect is beyond our ken. What concerns us most at 

 this moment is that a similarity exists between the vicissitudes of 

 the water content and the rate of embryonic growth — that the per 



