GREAT STEPS IN EVOLUTION 73 



up in a tumbler some white of egg, some 

 yolk of egg, some casein from milk, and so 

 on, we have got a mixture of proteids, one 

 excellent to feed protoplasm with, but we 

 have not got protoplasm itself. Our tumbler- 

 mixture is only a fortuitous concourse of 

 proteids; whereas protoplasm is an integrate 

 of proteids, perhaps with fats and amyloids as 

 well a, fortunate combination of molecules in 

 instable, even mobile, yet enduring equilibrium. 



It is probable that the potency of living 

 matter is in part an expression of the com- 

 plex inter-relations of the diverse proteids 

 and other substances of which it is com- 

 posed. No single substance may mean very 

 much, but in combination they are irresistible. 

 Indeed we may compare protoplasm to a 

 successful firm which owes its success to an 

 unusually fortunate combination of partners 

 of inventive, organizing, administrating, 

 pushing, competitive and other geniuses ! 



But there is something more. The firm 

 works as a unity, and this is its essential 

 secret. It is unified from within, whether 

 by a common purpose, or by the predominant 

 will of its leading partners, or by something 

 of both. And the organism has likewise its 

 secret, its internal unity, which we are still 

 far from understanding. 



