Evolution by Expansion. 
29 
1S77.J 
can have built up an ever-progressing fauna and flora, infinite 
in variety, but always subject to definite laws, always re- 
taining their typical characters, while evincing adaptation 
the most perfect to the conditions of existence. 
It is not my intention to review the numberless objections 
to the theory of natural selection that have been urged by 
different naturalists, prominent among whom are Mivart, 
Nageli, &c. ; but to show how completely and fully the theory 
of an innate power of growth or expansion is borne out by 
the most important phenomena of morphology, and embryo- 
logy taken in connection with palaeontology. 
In advocating the theory of expansion, I am prepared to 
admit that natural selection has probably been a subsidiary 
agent, and one of some importance ; but the agency I believe 
to have mainly effected what Darwin ascribes to natural 
selection would seem to be a subtile force inherent in all 
organisms, too potent to be disturbed in its adtion to any 
considerable extent by extraneous influences, and destined 
to work certain definite results in a definite period of time ; 
in short, a power of growth or expansion implanted in all 
organisms, when launched into existence, and extending 
through all time. This power of growth would also appear 
to develop in all organisms similar features, subject to the 
modifying effects of climate, conditions of life, &c., at the 
same stage of expansion. 
I will consider this definition of the Innate Force in refer- 
ence, first, to the phenomena of Morphology. 
All plants and animals are classed according to their 
morphological characteristics, and not with reference to 
their habits, &c. The habits of different species belonging 
to the same class are often as different as it is possible to 
conceive, and they use homologous parts, — that is, corre- 
sponding portions of their structures made on the same 
model or type for widely different purposes. That is to say, 
species preserve their type no matter what be their condi- 
tions of existence. Conformity to type is thus the para- 
mount law in the formation of species ; adaptation to the 
conditions of existence a secondary law. Darwin considers 
the latter law to be the higher : were this the case we 
should not find the former asserting itself with unvarying 
persistence in the most diverse adaptations of homologous 
parts. Type is persistent through every adaptation. Adapta- 
tion is nothing more than a modification of type to suit 
certain conditions. Adaptation may be the result of natural 
selection, or it may not ; but type cannot be, as its existence 
is incontestibly independent of, and has no connection with, 
