I.— PHYSIOLOGY. 213 



to its survival. Where energy is necessary for such synthetic rearrange- 

 ments of adjacent matter — where, that is, the rearrangement involves 

 coercion of atoms into positions of strain in which they have the potential 

 energy of position which we call chemical energy — this energy may be 

 derived from the radiant energy of the sun or from the combination of 

 oxygen with adjacent organic matter. In the latter case the combination 

 is again a manifestation of the power of ordering the disposition of sur- 

 rounding molecules and directing their movements so that they behave 

 as in other circumstances they would be but little j^rone to do. The 

 energy so liberated, besides contributing to the formation of new living 

 matter or of the material to be used in its formation, may serve in other 

 ways to promote the processes by which life is maintained. It may 

 accelerate them by imparting increased kinetic activity or rise of tempera- 

 ture, or may bring about movements that are resisted by external forces, 

 and so enable the living system to do work. 



This is all merely a restatement of the commonplaces of biology, 

 necessary only as part of the attempt to correlate them physiologically 

 with the fundamental property of that which is alive to regenerate itself 

 at the expense of material that is not alive. This faculty implies the 

 power of introducing order into the chaotic movements of adjacent matter 

 in conformity with patterns that it possesses. It is a facultv resident in 

 material that is capable of incalculable variation. The number of permuta- 

 tions of its parts that are possible without aifecting the results of such 

 analysis as is practicable defies calculation. Their calculation, were it 

 possible, would lead to figures that are so large as to mean no more than 

 the dimensions of the universe. Some of these permutations confer 

 synthetic powers which others do not. When they appear, are they not 

 what biologists call, for short, mutations ? But when they appear, if the 

 retain the power of self-regeneration, and if they minister to its mainten- 

 ance, they will ipso facto survive. For whatever promotes persistence 

 of this power must itself survive. 



A disposition of matter in molecules or aggregates, unstable and 

 incalculably variable, that has and retains the power of determining the 

 disposition of matter not yet so disposed in such a way as to conform to 

 its own disposition or to patterns which help it to exercise this power, 

 is all that must be premised for the whole of evolution to follow. Varia- 

 tions that do not or cease to contribute to the retention of this power do 

 not survive. The condition of survival is ministration to self-regeneration ; 

 that is, to the maintenance of life. 



Before the days of vertebrates, in pre-Silurian time, an unstable 

 variation in the disposition of atoms and organic combinations of atoms 

 occurred in certain types that was mainly protein in character, a protein 

 to the making of which little short of 200 amino-acid links must contri- 

 bute. Coupled to this protein, which probably is not the same in all 

 species of animals in which it is found, is another group containing iron 

 that is probably always the same. This group is of remarkable nature, 

 and is closely related to one that occurs in the far older substance 

 chlorophyll. This complex substance, hajmoglobin, had the power of 

 attaching to itself two atoms of oxygen for each atom of iron that it 

 contained in such a way that it could be readily detached and made 



