1883.] Growth and Development. 723 
ganglia ; and the growth of the connective tissues may be insti- 
gated by muscular pull, gravitative pressure and other general 
force influences discharged into the body. 
Thus there is some reason to believe that all animal growth 
and transformation is instigated, directly or indirectly, by the in- 
fluence of external motor force, which penetrates the body, 
induces oxidation (which could not otherwise take place) and 
produces some phase of animal action, succeeded by an increased 
blood flow to the point of activity and a subsequent special nutri- 
tion. The indirect results of this principle—those of mental in- 
stigation—arise from previous individual or from ante-natal con- 
tacts, whose influence is stored up in the organism as a directive 
energy. The ante-natal contact influences tend to the develop- 
ment of the type; the individual to variations from the type, 
which grow decided when new forms of contact, arising from 
changed external conditions, act upon the body. 
If we consider the life of an individual animal, it may seem 
as if the idea here advanced is not sustained. For the inherent 
physical and mental aptitudes of the body control its develop- 
ment far more than external influences. But what is the life of 
an individual? The aptitudes mentioned were derived from 
parents, who in turn derived aptitudes from their parents, and the 
parental line might be followed back, if we adopt the evolution 
hypothesis, through an excessively long series of animals until 
it reaches its source in the primitive speck of homogeneous pro- 
toplasm. The complete life history of an animal really includes 
the organic histories of all these precedent forms, though it be 
millions of years in the making; and the germ of every advanced 
animal is the record of an interminable era. But nowhere along 
the line will we find all the organic aptitudes which are displayed 
in the final form. These physical and mental characteristics were 
gradually gained. The original rhizopod did not have them. 
Whence, then, did the man obtain them? The original rhizopod 
was not without its inherent characteristics. It possessed chemi- 
cal differentiations to which the difference of sex may be ascribed, 
and differences in the relations of its internal and 
regions to which the separation of the motor aad nutritive func- 
2 For illustrations of this fact see chapter on “ the law of use and effort” in paper — 
on “The Method of Creation of Organic Forms,” by Professor E. D. Cope, Pro- 
ceedings of American Philosophical Society, Dec. 1 sth, 1871. 
VOL. XVIt.—no, vit, 49 
