BIOLOGICAL STUDIES ON 7 CORVMORPHA. 



28l 







though it may occur after section of the column even below the 

 fru-tular /one, in the extreme basal region, is most frequent in 

 piece- (lit from the column in its distal half. 



At the very 1>< -ginning of my observations on the regeneration 

 of C'i>r\nii>r{fhii, I was Struck with two facts : (I) that a -egment 

 from tin- di-tal half of the column and including the hydraiuh, 

 do.-- IK it d.-\elo|. ,i h \dranth at the proximal end until the original 

 hydrant h i- removed; (2) that when the original hydranth ha- 

 lii-eu reino\ . -d. the proximal hydranth dexelop-, umler normal 

 condition-, in. ire slowly than the distal another indication, it 

 ma\ Li- mentioned, in passing, of the initial polarization ol the 

 ( < .luinii. 



Tin-, facts suggested the possibility that, 1>\ dela\ing the 

 development of the distal hydranth on a regenerating piece until 

 the pioxiiiial h\dranth should 

 h.i\c n.ii lud an advanced stage 

 oi di \clopiueiit, the initial polar- 

 i/atii-ii mi-Jit lie completely re- 

 ed. A. . ' .idingly, in the 

 Mimim-i . .1 i'M>2, I performed the 

 I'ollou ing experiment. 1 A seg- 

 nieiit \\a-cut I loin the distal hall 

 o| .111 a\erage polyp (Fig. I, A). 

 h \\a- linn inserted, and the 

 di-lal cut Mirface held against 

 tin- gla--- IK. it on i . .f th.- aquarium F 



|.\ the uei^lit "I a -trrl iici-dle 

 through the distal region I 

 1. />'). The |.n. \imal end was 

 and the Mem \ertical. At 

 tin' end of three da\ -. a ludianth lloiiri>hed at p, though tin re 

 \\a- -ign neithi-r "t tentacle- nor fru-tule- at <l. The needli- was 



removed. I"\M> <la\ - later a -mail hydranth had appeared al <1 



(Fij [, I .\\ith three di-tal and f. -ur pn.vim.d tentacli'>, sonu- 

 \\hat iriegularK arranged, probal >1\ < .\\ing to the \\oiind let't l'\ 

 the needle and t.. other adverse conditions to \\hich that end 

 max ha\e l>eeii -ul.jected \\heii |>re ed against the -til stratum. 



nnti'.l in tin ixurred under starvation conditions. 



B 



FIG. i. 



