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of excellence of structure. So, likewise, it is evident that inasmuch as the 
several groups of vertebrates may be ranged into a series ranging from simple 
to complex, and possess certain common elements of structure, the Creator 
at first projected a scheme of organization, and gradually improved upon it.” 
This is assuredly travelling beyond the limits of legitimate speculation. The 
existence of a series of common characters in all classes of vertebrates, by no 
means involves the fact that the Creator designed them upon any particular 
model. Man, owing to his finite comprehension, is compelled in his pro- 
cesses of construction to employ some scheme, in order, as it were, to keep 
him in the proper track. Were it not for this, he would be unsuccessful. 
But no truly reflective mind can be satisfied with a doctrine which teaches 
that an omniscient Creator either required or adopted a guiding plan. Not- 
withstanding Professor Owen’s ingenious attack on the value of the study of 
development, by asserting that embryology shows nothing of homology, he 
cannot defend his theory against the charges urged against it in Mr. Huxley’s 
Cromian lecture. 
Development is, in all cases of philosophic inquiry, the true key to know- 
ledge. If we sought to discover the nature of a language, and its relation to 
some other tongue, should we not endeavour to trace the history of its growth ? 
Did we content ourselves with mere existing resemblances, we might be led 
— and those who do so are led — into the most extravagant conclusions. So, 
in the case of homology, or relationship of parts in anatomy, we must not take 
the structure as it is, but we must go back in its history, and observe and 
study the processes by which it came from what it was. Then by comparing 
the results of this mode of inquiry with those obtained from a similar way 
of investigation in the case of other structures, we may hope to arrive at 
valuable knowledge. Professor Owen cannot be said to appreciate the full 
importance of the developmental method. Indeed, the mere circumstance 
that he calls homology name-sakeism, sufficiently shows his views upon the 
subject. “ Homological anatomy,” he says, “ seeks in the characters of an 
organ and part, those chiefly of relative position and connection, that guide 
to a conclusion manifested by applying the same name to such part or organ, 
so far as the determination of the name-sakeism or homology has been carried 
out in the animal kingdom.” 
Not the least important feature in the work before us is, that it contains 
a partial concurrence, on the part of the author, in the theory of natural 
selection. Professor Owen does not believe that this guess-endeavour , as he 
terms it, explains the relation between Troglodytes and Homo ; but he goes 
so far as to admit the action of external influences in destroying some species 
and preserving others. His remarks on this point deserve notice : — “ The 
actual presence of small species of animals in countries where larger species 
of the same natural families formerly existed, is not the consequence of any 
gradual diminution in the size of such species, but is the result of circum- 
stances which may be illustrated by the fable of the ‘ Oak and the Reed ’ — 
the smaller and feebler animals have bent and accommodated themselves to 
changes which have destroyed the larger species. They have fared better 
in the ‘ battle of life.’ ” Of the plan of the present volume there is not much 
to be said. It treats exclusively of the Hcematocrya , or cold-blooded animals. 
The author first gives a general account of the characters of vertebrates, and 
