THE AXIAL GRADIENTS IX HYDROZOA. 



1855 



continue to grow at the expense of the more basal levels, which 

 are gradually resorbed. Such growth may continue for week- 

 and extend over many centimeters, being ended only by cxhaus- 

 i of nutritive material. It is discussed more fully in a later 

 section. 



When the degree of acclimation or recovery is such that the 



lients attain or approach their normal physiological condition. 



hydranth-Mem structures develop. In differential acclimation 



and ondition is usually attained only gradually, 



Mt-ntly the first outgrowths are almost invariably stol 

 and the-c transform later into hydranth-stem a\e> as in Fig. i', 



21 



or -i\r ri>r 1 >y budding to such axes as in 1-i^s. 20 and 21. In 

 tlu--e ti^uif- thr animal- are viewed from the nde, the original 

 1 ir\ al body and tin- M< 'Ions are in contact with the bottom and the 

 hydranth-stem a e more or less erect. 



\\ ith the apprarance of hydranth-Steni a\e> the further -mwth 



