Ill 



PRIMARY INDUCTION 



EXPERIMENTAL DATA 



377 



Fig. 45. Method used to insert an implant in the blastocoele in such a way that it will stay 

 in the chosen location, (a, b, bi) An uninvaginated piece of the dorso-marginal zone is 

 dissected from an early gastrula (a) and a fragment of the same size is cut from the ventral 

 wall of the blastocoele in another gastrula (b). Both pieces are apposed, inner sides together, 

 for 2-3 min. ; as soon as they adhere together, they are used to fill the hole created in (b), as 

 shown in (bi). (a', b, b') The same process is used in the case of an invaginated part of the 

 blastoporal lip. From Schechtman, 1938, modified. The Japanese authors also used a simpli- 

 fied method oi^ affixation, consisting in scratching the inner side of the blastocoele wall and 

 placing the inner side of the graft against this modified region. 



Fig. 46. Mapping the fate of the early (a) and somewhat more advanced (b) newt gastrula 



by vital staining. In (c) the embryo at the early neurula stage is seen from its dorsal side 



with the neuroepithelium removed. See text. From Okada & Hama, 1945b. 



Literature p. 483 



