Experiments on Polarity in Tubularia. 



571 



be somewhat retarded, that of the longest pieces Httle if at all. 

 Since in each set the pieces were of approximately the same 

 length, the retarding influence is probably constant for each 



\x V 



■ > 



"V 



'^ "^w^ \r ^ 



\<c vr^^ 



^ W W V V H Y V 



-^ 





K 



A 



Fig. 5. 



series, 

 behave. 



a 1/ I'' I 1/ i¥ I' 



Fig. 5 gives an idea of the way in which these pieces 



The remaining series are given in 

 a different form. In each case the 

 old oral end is at the top in the 

 series. Those polyps that emerged 

 simultaneously have the same num- 

 ber; thus the first to emerge are 

 numbered i, the second 2, etc., the 

 figures being placed near that end 

 at which the polyp 

 formed. In Tables 

 IV and VI the fig- 

 ures I, 2, 3, 4, 5 in- 

 dicate observations 

 made once a day for 

 five successive days. 

 In Tables V and VII 

 the figures indicate 

 the sequence for Table V. 





TARi.E IV. 



