THE PRINCIPLES OF BIOLOGY. 
189 
But deduction brings us to a conclusion in harmony with 
that inductively reached, for all organisms are continually 
passing into new environments, which, if they (the organisms) 
are to survive, must be met, as individuals, by re-adjusted 
balance of functions and correlative adaptation of structure, 
and as species by natural selection or survival of the fittest. 
Tims we see that organic evolution conforms to the 
universal laws of the redistribution of matter and motion 
conformed to by evolution in general. 
Yet, strong as is the evidence presented by the organic 
world as a whole of the evolution of organisms, we shall see it is 
greatly strengthened when we come to consider “ the ensemble 
of vital phenomena presented by each organism.” 
Appendix to Yol. I. 
The Appendix consists of a letter written in 18G8 for 
publication in The North American Tier lew, but declined by the 
editor in pursuance of a general rule. The subject matter is 
of such vast importance, as elucidating some of the most 
recondite portions of The Principles of Biology, as replying 
to certain serious and able criticisms, and as demonstrating 
that the evolution of the organic from the inorganic is a 
necessary deduction from First Principles, that it is deeply to 
be regretted that the necessary limitation of space renders an 
adequate exposition of it impossible. In the preface to the 
system it was explained that on account of the largeness of 
the projected work, the author decided to omit the two chapters 
on Inorganic Evolution which would otherwise have preceded 
The Principles of Biology, and this necessary though regrettable 
hiatus appears to have led some critics to suppose that Mr. 
Spencer believed in spontaneous generation instead of in 
generation by evolution. The way in which this latter process 
has operated in accordance with the great fundamental laws 
of the instability of the homogeneous and of the persistence of 
force, by the continual compounding and re-compounding of 
the elementary atoms, and then of the resulting Complex 
Molecules, until after the lapse of vast periods of time such a 
substance as protein comes into existence, from which still 
further modifications upon modifications at length evolved 
the lowest living forms, which at first without organs after¬ 
wards attain these attributes, is explained with an amplitude 
of scientific illustration and minuteness of detail requiring for 
its due comprehension the most careful study. It is here only 
possible to thus briefly indicate the nature of the propositions 
and the lines of argument followed in their demonstration. 
