noe) Sergius Morgulis 
average number of segments regenerating for equal periods of 
four days from the anterior level, while the horizontally striated 
columns are representative of the numbers of segments regener- 
ated from the posterior level. In accordance with our present 
state of knowledge it seems fair, therefore, to assume that the 
greater output throughout the whole process of regeneration 
indicates a condition of higher physiological activity in one case 
than in the other. 
i} 
24 days 
Fig. 5 This is to show the relation between the rates of regeneration from two levels during the 
regenerative process. The obliquely striated columns represent the rate of regeneration from the 
anterior, while the horizontally striated columns represent the rate of regeneration from a posterior level, 
for similar periods of time. 
Now, from a study of posterior regeneration what can be 
learned concerning our second problem, which, as stated in the 
beginning of this chapter, is to ascertain the exact relationship 
between the process of formation of new segments*and their sub- 
sequent growth ? . 
When we examine regenerating tails about the sixteenth day 
after the operation, we usually find them as yet very small; in 
