EXTENSION OF EVOLUTIONARY THEORIES 335 



conceive that a determinant, which has increased in 

 size within the mother through the good supply of food, 

 will, by reason of its size, attract more food to itself in the 

 daughter. When the mother's germ-cell divides to form 

 the daughter-cells, we know that in the earlier segmenta- 

 tions of the ovum all the determinants are split into 

 halves, because first of all must be formed the germ-cells 

 of the daughters, and these must contain all the basic 

 particles. When the determinants come into action in 

 the later segmentations, and gradually build up the 

 body of the daughters, some of the first cells divided, 

 the germ-cells retain all their determinants in a quiescent 

 state. Hence if a determinant became larger in the 

 mother owing to a good supply of food, it maintained 

 this size in the germ-cells of the daughters as well, as 

 after cleavage it always grew again to its normal size. 

 And, being larger, it needed more nourishment than the 

 neighbouring determinants that remained small. Owing 

 to its volume it, as it were, drew to itself the stream of 

 food circulating in the germ. On account of this supply 

 of food it became still larger, and retained its size in the 

 ovum of the grand-daughter, where it again attracted 

 food, and became larger still. The size increased in 

 each generation, the determinant grew larger and larger, 

 and hence the part of the body that it built up showed 

 a corresponding steady increase or, in other words, a 

 definitely directed variation. 



Does this enlargement of a determinant and the 

 corresponding organ proceed indefinitely ? If this were 

 the case, there could be no such thing as a specific 

 type. As the nutrition is exposed to irregularities 



