334 DARWINISM AND THE PROBLEMS OF LIFE 



of the body, consist of living matter, and so must receive 

 nourishment. Their food must be matter that is 

 found in the germ-cell, or passes into it from the body. 

 This matter must, of course, be fluid and must flow 

 round the determinants. 



Nowhere in nature do we find absolute equality, and 

 so the fluid nutriment will not equally reach all parts of 

 the germ-cell. Hence a determinant will receive some- 

 times a fuller and at other times a thinner supply of food. 

 If it finds plenty of food, it will grow strong and sound, 

 as all living matter does when it is well nourished. 

 Another determinant will chance to have a worse 

 supply of food, and become weaker. 



When the determinant is thus enfeebled by happening 

 to receive a poor supply of nourishment, it will, if an 

 animal is developed from the germ, have less power to 

 build up the organ it represents, and the organ also will 

 be feeble. And when a determinant is strengthened in 

 the germ by a plentiful supply of food, it will afterwards 

 build up its particular organ in greater strength. Thus 

 we see that the variations we find in children of the 

 same mother at birth are due to chance differences in 

 the supply of food to the ova. While the ova lay unde- 

 veloped within the mother's body, the determinants were 

 differently fed by the varying stream of nourishment, 

 and when they afterwards come into action they show 

 differences in the building up of their respective organs. 

 Hence the accidental irregularities in the supply of food 

 in the germ are the roots of variations. 



All living matter is able to accomplish work in pro- 

 portion as it is strengthened by food. We can thus 



