7^6 Florence Peebles 



developed. A much larger per cent of aboral hydranths formed 

 on A in the control, and also more oral hydranths on C in the con- 

 trol. This seems to indicate that the process of hydranth forma- 

 tion at the grafted ends of these pieces affects their later behavior. 



Table 7 and Table 8 show very definitely, that the results after 

 the second operation are not modified by those following the first 

 unless the period between the two operations is sufficiently long 

 for them to get a start. In the first place (Table 7) the number of 

 oral hydranths on the distal half of the original distal component, 

 is much larger than that on the proximal half, while there are 

 more aboral hydranths on the proximal half than there are on the 

 distal half. This is not the case (Table 8) when the second opera- 

 tion follows the first after a very brief period. Secondly, the 

 number of aboral hydranths on the proximal end of the original 

 proximal component is much larger than the number on the distal 

 half of the same component, and the number of oral hydranths 

 on its distal half is greater than on the proximal half. This is 

 not the case when the time between the first and second operations 

 is reduced. 



Experiment ^. In the fourth series of experiments the two 

 components were grafted together in the way described above, but 

 this time the level of the second cut was changed, making the 

 piece A (Fig. 10) consist of the greater part of the distal compo- 

 nent while B (Fig. 10) was made up of a short basal piece of the 

 distal component grafted on the oral end of the proximal compo- 

 nent. The third cut (Fig. 10,3) was made nearer the aboral end 

 of the proximal component thus making C shorter than in the 

 preceding experiment. A series of sixteen grafts of this descrip- 

 tion are represented in Table 9. 



If we compare the rate of development of hydranths onA,B, and 

 C we find oral hydranths on A and C appearing at about the same 

 time, also those on the oral and aboral ends of B. The per cent of 

 hydranths on the oral and aboral ends of ^ and C was about the 

 same as that in Experiments i and 3. The proportion of double 

 hydranths at the region of the graft was larger, and also the num- 

 ber of aboral hydranths on the distal end of the proximal compo- 

 nent. When this experiment is modified by decreasing the time 



