LAW OF INHERITANCE AND TRANSMISSION. 11 
other words, and the organism changes. The plants and 
animals of the mummies and monuments of Egypt are prob- 
ably the same as those now living in that country, because 
the climate and soil have remained the same. 
The assemblages of life that have successively peopled the 
surface of the earth, and which are geological time-marks, 
have probably become extinct because they could not adapt 
themselves to more or less rapid oscillations of continents 
and islands, to consequent changes of climate and the in- 
coming of destructive types of life. This probably accounts 
for the origin, culmination, and extinction of different 
types of life. The earth has been, and still is, in a state of 
unstable equilibrium. Organic life has been and is even 
now, in a degree, being constantly readjusted in harmony 
with these changes of the earth’s surface and climate. Thus 
this adaptation of organs to their uses, of animals to their 
environment, the laws controlling the origination of new 
forms of life and the extinction of those which have acted 
their part and are no longer of service in the economy of 
nature, is part of the general course of nature, and evinces 
the Infinite Wisdom and Intelligence pervading and contin- 
ually operating in the universe.* 
Coupled with variability is the law of inheritance and 
transmission of variable parts, and the habits thus induced 
by the variation of parts. It should be observed that the 
portions which vary most are the peripheral parts—7.e., 
fingers and toes, tentacles and antenne, the skin and scales 
and hair; it is by modifications and differences brought 
about in those parts most used by animals that the multi- 
tudes of specific forms have resulted. There is, as Darwin 
states, a general tendency of organisms to vary; the laws 
accounting for this tendency to vary have yet to be formu- 
lated ; though the attempts of Lamarck in this direction 
laid the way for the discovery and application of the funda- 
* That animals and plants are self-evolved, that the world has made 
itself, and that all is the result of so-called physical and biological laws 
operating from within outward, is as inconceivable as the medieval 
dogma that animals and plants and the earth they inhabit were made 
in the twinkling of an eye. Sce the concluding chapter on Evolution. 
