66 thp: germ-plasm 



stage would thus be known, and we might in imagination then 

 arrange them in such a way that it w^ould be possible to picture 

 their disintegration into the respective series of smaller and 

 smaller groups. 



Such a representation of the architecture of the id of germ- 

 plasm would, however, never be an accurate one, because its 

 parts must be subjected to incessant slow displacement during 

 the growth of the idioplasm and in the course of development. 



This brings us to the second factor which takes part in the 

 ontogeny of the idioplasm, viz., the uneven rate of Diultiplication 

 of the deterjuiiiants. An id of germ-plasm composed entirely 

 of similar determinants, would have to retain its original archi- 

 tecture even during vigorous growth and continued division ; 

 just as would be the case in one of the lowest forms of life — a 

 Moner — consisting of a number of identical biophors, which 

 must remain the same throughout all the divisions which it un- 

 dergoes. In a germ-plasm consisting of a number of different 

 determinants, a perfectly even rate of multiplication cannot be 

 assumed in the case of all of them. For the difference between 

 two determinants depends presumably on the differences in the 

 nature, number, or arrangement of their constituent biophors, 

 and the latter differ again in their molecular structure, i.e. in their 

 essentia] physico-chemical properties. Hence the determinants 

 will behave differently as regards their reaction to external influ- 

 ences, — more especially in respect of their rate of growth and 

 increase, — according to their constitution. The same conditions 

 of nutrition will therefore stimulate one to a faster, and another 

 to a slower, growth and corresponding multiplication, and thus 

 an alteration in the proportional numbers in which the indi- 

 vidual kinds of determinants are present in the germ-plasm must 

 occur continually in the course of embryogeny ; for the latter is 

 connected with a constant growth of the idioplasm, and therefore 

 also with a continual increase of the determinants. This 

 must cause a disarrangement in the architecture of the germ- 

 plasm, in which process the third factor concerned in these 

 changes, viz., tJie forces of attraction in tJic determinants, may 

 take part. 



The assumption of such forces can scarcely be avoided. P^or 

 it is very probable, a priori, that vital units do act upon one 

 another in different degrees, and this view is supported by a con- 

 sideration of the processes of nuclear division, together with the 

 distribution of the primary constituents in ontogeny. 



