34 An Examination of Weismannism. 



into these successive formations of idio-plasms-A the 

 less of it remains for further differentiation,, till, at the 

 last stage of ontogeny, all the original idio-plasm-B 

 (germ-plasm) has been thus changed into idio-plasms-A 

 severally distinctive of all the somatic-tissues a, b, c 

 — x,y, #, — save only the portion of it which has been 

 carried through all these ontogenetic stages in a 

 wholly ^^differentiated condition, for the purpose of 

 securing the p >hy i 'ogene 'tic production of the next gener- 

 ation. And this, of course, is secured by the portion of 

 undifferentiated germ-plasm in question being de- 

 posited in the nuclei of germ-cells, at whatever stage of 

 the ontogeny these may be formed. 



Finally, it is evident that, at each stage of the 

 differentiation of idio-plasm-B into idio-plasms-A, 

 the portion concerned must be capable of self-multi- 

 plication to an almost incalculable extent, — yet this 

 only as idio-plasm-B of the particular kind required for 

 constructing the idio-plasm-A which is appropriate to 

 the particular stage. Such is a necessary deduction 

 from the terms of Weismann's theory, inasmuch as we 

 know that at each of the ontogenetic stages there is 

 an incalculable multiplication of cells belonging to that 

 stage — cells, the " cytoplasm " of which necessarily 

 presupposes for its formation its own appropriate 

 idio-plasm in both kinds, and this in similarly increased 

 quantities. 



From the above theory it follows that an explana- 

 tion can be given of the healing of wounds (as in 

 ourselves"), of the regeneration of lost parts (as the 

 limb of a newt), or even of the reproduction of an 

 entire organism from a mere fragment of somatic- 



