Ent. 



d 



Fig. 69 

 Homoiogenetic induction of neural folds by brain tissue. « A free-swirnming 

 larva of Triton taeniatus, with limbs {Extr.) and balancer (T. , from which a 

 portion of brain tissue was grafted into b, a young gastrula of the same species ; 

 U blastopore, c, The same embryo, 68 hours after the operation from the lett 

 side, showing the graft {Impl.H.). d, Section through the graft and the induced 

 neural tube (Med.ind.); Impl.Fas. nerve fibres, and Impl.Gangl grey matter, ot 

 the highly differentiated graft; Ent. endoderm, V.D. foregut of host embryo. 

 (From Mangold, Ergehnisse der Biol, in, 1928.) 



