288 THE ASCENT OF MAN 



child. So far from its chief manifestation being 

 within the sphere of sex it is in the care and 

 nurture of the young, in the provision everywhere 

 throughout Nature for the seed and ^%g^ in the 

 endless and infinite self-sacrifices of Maternity, that 

 Altruism finds its main expression. 



That this is the true reading of the work of 

 this second factor appears even in the opening act 

 of Reproduction in the lowest plant or animal. 

 Pledged by the first law of its being — the law of 

 self-preservation — to sustain itself, the organism is 

 at the same moment pledged by the second law to 

 give up itself Watch one of the humblest uni- 

 cellular organisms at the time of Reproduction. 

 The cell, when it grows to be a certain size, divides 

 itself into two, and each part sets up an independent 

 life. Why it does so is now known. The proto- 

 plasm inside the cell — the body as it were — needs 

 continually to draw in fresh food. This is secured 

 by a process of imbibition or osmosis through the 

 surrounding wall. But as the cell grows large, 

 there is not wall enough to pass in all the food 

 the far interior needs, for while the bulk increases 

 as the cube of the diameter the surface increases 

 only as the square. The bulk of the cell, in 

 short, has outrun the absorbing surface; its hunger 

 has outgrown its satisfactions ; and unless the cell 



