102 



THE GER.M-PL.'VSM 



Let US now return to the question of regeneration. If each 

 cell in the fully-formed bone only contains that kind of idioplasm 

 which controls it. and which is therefore the molecular expres- 

 sion of its own particular nature, it would be impossible to 

 understand how the regeneration of the bone could be effected — 

 when, for instance, it had been cut through longitudinally. 



Bumervs J^erSti 



s^adiusfTIlna-rHanA 



^J- 



m 



llx)^ 



Rod,: 



Det 

 ' s ma 



/l)ei\6-2(; 





J)etSS3-3S 



Detjm 



radiali. 



rad.t 



radiate^ 



J)ec.-tO, 

 ^l3tacarp.I 



radiaikjPwUt 







tdn-Caiyms 



Ver.2S-3S 

 ''fJ^uln.Metacarpus 



ul/ia/v/bi^ct. 



Dig/ 



J>etJ21^fr3t 



MetacarpJJ 



J)ftM 



PhaiSn^- 



Ptm 



VhalM^m 

 Ph, 



J}iguusIV 



WtM 



VeC-33-3S I 



■^^^^rrr MtOCOrpiCS 



'VUi 



PluUM PltaiM 

 Fig. 3. — Diagram of the Cell-Generations in the Fore-Limb of a Triton. 



^5»• 



Supposing that a stimulus, produced by the injury, caused the 

 cells of the injured part to undergo multiplication : bony tissue 

 would then, indeed, be developed, but a bone of a definite shape 

 and size would not necessarily be formed. The formation of a 

 definite bone can onlv take place if the proliferating cells possess. 

 in addition to their active determinants, a supply of determinants 



