350 Florence Peebles 



In a third series A measured .8 mm. This time the tip was 

 removed as scon as the piece was cut from the stem, so that no 

 time elapsed between the first and second operations. 



SERIES 3 A 



Complete hydranth o 



Distal tentacles 7 



Double row i 



No regeneration 4 



Total number 12 



In this series one of the "incomplete" structures, i. e., a hy- 

 dranth composed of two distal rows developed. This result is 

 often obtained from short pieces. The piece A in this experi- 

 ment was shorter than the short pieces from which Child ('07b) 

 obtained a complete hydranth. 



In a fourth series the anlage of the proximal row of tentacles 

 was just visible as a faint red area. The length of the piece 

 removed was .6 mm. The time between the operations was forty 

 hours. The following table gives the results from thirty pieces. 



SERIES 4 A 



Complete hydranth o 



Distal tentacles 25 



No regeneration 5 



Total number 30 



Here no complete hydranths developed, while twenty-five 

 formed the distal row which was probably already laid down 

 when the two pieces were separated. 



In a fifth series the piece A was removed immediately. This 

 time the tip cut off exactly equaled the average area of the entire 

 anlage (Fig. 23, P). 



SERIES 5 A 



Complete hydranth 12 



Distal tentacles o 



No regeneration 3 



Total number 15 



