258 Theories Treating of Inheritance 



second place if this character instead of consisting in a 

 general change existing in all the cells concerned, is 

 rather any given local morphological or physiological 

 modification whatever of definite organs or tissues, it 

 will evidently be impossible to represent this modification 

 as acquired at the same time also by the germ plasm, 

 since in the latter these organs and tissues do not exist. 



It seems nevertheless that Cope's meaning is that 

 each even local morphological or physiological modifi- 

 cation of the soma must always correspond at the same 

 time to a certain specific, dynamic state of the proto- 

 plasm in general, and that it is this new dynamic state 

 which would be acquired at the same time by the proto- 

 plasm of the soma and by that of the germ. 



For to explain "the way in which the influences which 

 acted upon the general structure reach the germ cells," 

 he builds up his "dynamic theory," taken from the do- 

 main of molecular physics, and has recourse to that spe- 

 cial form of energy mentioned above, which he calls 

 "bathmism." And this bathmism would consist acord- 

 ing to this author "in a mode of motion of the molecules 

 of living protoplasm by which the latter build tissue at 

 particular points, and do not do so at other points." 



"This action is most easily observed in the begin- 

 nings of growth, as in the segmentation of the oosperm, 

 the formation of the blastodermic layers, of the gastrula, 

 of the primitive groove, etc. In the meroblastic embryo 

 the energy is evidently in excess at one point of the 

 oosperm and in defect at another. This is a simple 

 example of the location of growth force or bathmism. 

 In all folding or invagination there is excess of growth 

 at the region which becomes the convex space of the 

 fold; i. e. a location or especial activity of bathmism at 



