RECONSTITUTIONAL PATTERNS IN EXPERIMENT 379 



dominance of the host stem and the gradient of the donor stem are both 

 factors in determining effectiveness of the implant as inductor. In these 

 experiments the implants were 1/4 sectors of transverse pieces as short as 

 could be cut and were implanted without any attempt at orientation. 

 When isolated, such pieces usually develop into partial apical forms but 



A 



Fig. 127, A-F. — Determination by induction of new axiate patterns by small grafts in 

 Corymorpha. A-C, developmental stages, part developing from graft shaded; D, new induced 

 axis consisting of proximal tentacles and stem; E, hydranth-stem axis and outgrowth on oppo- 

 site side of host stem induced by graft of distal half of fully developed manubrium, reconstitut- 

 ed distal host hydranth inhibited and host stem reduced distal to graft; F, determination of 

 bases at both ends of a piece of host stem by dominance of a new axis induced by a small 

 graft {A-C from Child, 1932c;; F, after Child, 1935). 



sometimes into complete individuals of extremely small size. When 

 grafted, they usually form only more or less of the apical part of the 

 manubrium. Rarely, however, development of the hydranth is so far in- 

 hibited that only proximal tentacles without manubrium develop (Fig. 

 127, D); in these cases the graft takes part in the tentacle development. 

 With more extreme inhibition only a stemlike outgrowth without hy- 



