196 DARWINISM TO-DAY. 



understand the theory of germinal selection, is this : Weis- 

 mann conceives the protoplasm of the cell nucleus to be 

 composed of units called biophors these biophors can also 

 migrate out into the cytoplasm surrounding the nucleus 

 which are the bearers of the individual characters of the cell. 

 The total character of any cell, its form, make-up, and spe- 

 cial properties, is determined by the totality of its biophors. 

 These biophors are not, however, such simple structures as 

 the atoms of the chemist ; indeed, they are to be looked on as 

 super-molecules, as complex groups of chemical molecules, 

 of determined character and arrangement. Moreover, as 

 these biophors are life-units, they possess the essential char- 

 acteristics of life, that is, the capacity to assimilate food, 

 to grow, and to reproduce themselves by division. The num- 

 ber of different biophors is almost inconceivably enormous ; 

 for it must equal the possibilities of variety in character 

 exhibited by, or capable of being exhibited by, all the cells 

 of the body. But as each biophor is made of many complex 

 molecules which may vary among themselves, and also vary 

 in their structural relation to each other inside the biophor, 

 it is not difficult, perhaps, to imagine the possible variety of 

 biophors to be equal to the possible variety of cell char- 

 acters. These biophors are conceived to be united into 

 fixed, indissoluble groups called determinants, each de- 

 terminant containing all the biophors necessary to deter- 

 mine the whole character of any one kind of cell. Like 

 the biophors the determinants can assimilate food, grow 

 and multiply by division. While in each specialised body- 

 cell there needs to be but a single determinant, namely, 

 one of the special kind conforming to the special kind 

 of cell, in the germ-cells there must be co'nceived to be 

 every kind of determinant which may be found in all 

 the body-cells taken together. But, fortunately, by virtue 

 of the determinants' capacity for multiplication it is 

 not necessary to assume that there exists in the germ a 



