'S93.] 75 
[Hyatt. 
would have been had it retained the form A. It involves a 
denial of the persistence of force to say that A maybe changed 
into A', and may yet beget offspring exactly like those it would 
have begotten had it not been so changed. That the change in 
the offspring must, other things equal, be in the same direction 
as the change in the parent, we may dimly see is implied by the 
fact, that the change propagated throughout the parental system 
is a change towards a new state of equilibrium — a change tending 
to bring the actions of all organs, reproductive included, into 
harmony with these new actions. Or, bringing the question to its 
ultimate and simplest form, we may say that as, on the one hand, 
physiological units will, because of their special polarities, build 
themselves into an organism of a special structure ; so, on the other 
hand, if the structure of this organism is modified by modified 
function, it will impress some corresponding modification on the 
structures and polarities of its units. The units and the aggregate 
must act and re-act on each other." ^ 
According to the theory of mnemogenesis, it can be reasonably 
assumed that "the habit or condition of life" which originates 
characteristics is attrilnitable to memory and the recurrence of the 
characteristics in successive forms to the mnemism of the cells act- 
ing inevitably and automatically, unless interfered with by other 
causes, as they come into being through the action of growth force. 
Tf this be true, the cells must move in accord as stated by Spencer 
in the same direction and reproduce the same characters in the 
same succession as that in which they first arose in accordance with 
the essential known characteristics of mnemism and genism. This 
gives a definite meaning to Spencer's otherwise vague statements 
of what might be called the drift of polarities towards equilibrium^ 
and enaliles an observer to compare the phenomena of mnemonics 
and genesiology. 
These remarks are not introduced here as an adequate statement 
of this hypothesis, but simply to show that mnemogenesis can 
claim to be a reasonable explanation, as open to positive jiroof as 
any other, and also to demonstrate tliat the term auxology or 
l)athmoIogy is inappropriate to cover the study of phenomena 
which can be attributed to forces so different in all their manifes- 
tations from those that govern the growth of an organism. 
iThe principles of biology, v. 1, p. 255-256, Amer. ed. 1872. 
