THE SYNTHETIC PHILOSOPHY: ITS THEORY OF EVOLUTION. 569 
changed, will, in the absence of the perturbing cause, resume very nearly 
their previous actions. The parts that depend on them will consequently, 
by and by, do the same, until, at length, by the reversal of the adaptive process, 
the organ at first affected will be brought back almost to its original state. 
This is a somewhat elaborate explanation of the process by which a commonly 
observed fact is brought about. It is not a new idea to people who have had 
experience with either vegetable or animal life that any changes wrought in either, 
by culture or breeding, are speedily lost if the artificial conditions be withdrawn. 
It is equally true in whatever direction the modifications have been wrought, for 
they will soon rise from a lower state to a higher, as well as fall from a higher toa 
lower when natural conditions are restored. How difficult it is to effect, and 
what sedulous care it requires to maintain such changes, is well known both in 
vegetables and animals. If, then, it is so difficult, and involves so many resisted 
changes to effect such modifications; if they are possible only within such 
narrow limits, never affecting the type; if they are of such doubtful transmission 
to posterity, while typical peculiarities are certainly transmitted, and if they are 
so difficult to maintain in the individual and so easily lost, it is difficult to see 
how species can have arisen in the way alleged. 
These facts might be held to dissipate the evolution theory in this part of na- 
ture, but there are further well established facts of science that have an important 
bearing upon this subject. The origin and form and composition of the germs of 
which all forms of life, vegetable and animal, are developed into embryos and sub- 
sequently into adult organisms, is pretty well known ; and Mr. Spencer presents a fair 
statement of the facts so faras he uses them. He says: ‘‘ The germ out of which a 
human being is evolved, differs in no visible respect from the germ out of which 
every animal and plant is evolved.” Mr. Spencer follows this with a statement 
of the process of germ development, showing that germs, indistinguishable in 
character if not indentically the same, in developing, travel a little way together 
and separate by degrees into the myriad forms of vegetable and animal life. These 
germs, in their ultimate state as germs, are but nucleated cells of protoplasmic 
matter, a description of which is given by Mr. Spencer in an appendix to his first 
volume of biology. He says: ‘‘In the early world, as in the modern laboratory, 
inferior types of organic substances, by their natural action, under fit conditions, 
evolved the superior types of organic substances, ending in organizable proto- 
plasm ; and it can hardly be doubted that the shaping of organizable protoplasm, 
which is a substance modifiable in multitudinous ways with extreme facility, went 
on after the same manner. As I learned from one of our first chemists, Prof. 
Frankland, protein is capable of existing under probably at least a thousand dif- 
ferent isomeric forms; and, as we shall presently see, is capable of forming, with 
itself and other elements, yet more intricate, compositions that are practically 
infinite in their varieties. Exposed to those innumerable modifications of condi- 
tions which the earth’s surface afforded, here in the amount of light, there in amount 
of heat, and elsewhere in the mineral quality of its aqueous medium, this extreme- 
