Fig. 77, ^-/.—Secondary modifications resulting from differential tolerance or condition- 

 ing and differential recovery. A-G, Arbacia; H-1, Dendraster. A, B, secondary modification 

 of apical region of gastrula in ethyl alcohol 2 per cent; C, prepluteus with elongated apical 

 region (oral lobe), a secondary modification characteristic with various agents; D-C, two 

 plutei in anal {D, F) and lateral (£, G) outline with oral lobe and ventral regions relatively 

 enlarged (characteristic with various agents); H, differential tolerance or conditioning with 

 LiCl m/90; /, J, differential recovery after 4^ hr. in LiCl m/30 from early blastula. 



