Factors in Regeneration 3^^ 



rate of development will be discussed later. For the present it will 

 suffice to state that because of this difference in the rate of devel- 

 opment, the latent period^ was not computed and the number of 

 complete polyps produced two days after their first appearance 

 (which may be the fifth or sixth day after amputation), and the 

 number produced within the next three days, were recorded. 



Regenerated 

 on 



Distal thirds 

 Middle thirds 

 Basal thirds 



TABLE 3 



2 days 



6754 9 "833 



TU^'T ? TINT'S 



6756 6 5 444 



y^^^g 11988 



6 3 14 «_ 3_ 5 3 4 



^U^gioiig^T 



We may conclude that the distal and middle pieces regenerate 

 practically the same number of hydranths but far in excess of the 

 basal pieces. 



Experiment /f.. The last experiment was modified to the extent 

 of using not the main stem but the lateral branches from the distal, 

 middle and basal regions of the stem. The distal branches were 

 small and delicate, quite different from the middle and basal 

 branches which owing to the smaller stems used, resembled each 

 other closely. 



TABLE 4 



Regeneration on 2 days 5 days 



Branches from distal region 37% 57% 



Branches from middle region 50% 79% 



Branches from basal region 68% 104% 



Regeneration of lateral branches differs at different levels. It 

 is greatest on branches taken from the basal regions (of small 

 stems) least on branches taken from distal regions. An expla- 

 nation of these phenomena will be attempted under the caption 

 01 ccenosarc. 



From the evidence already cited we may summarize as follows: 

 The distal half of a stem regenerates a much larger number of polyps 

 than the corresponding basal half. On the contrary, branches 



■•See Rate of Regeneration. 



