16 
POPULAR SCIENCE REVIEW. 
times we have the record of such failure. Now if the teleologist 
believed that fixity of species was nicely accommodated in the 
scheme of Nature to unchanging climates, to incapacity for 
migration among the several forms of life, and to contrivances 
for preventing the extinction of any, can he refuse to admit 
that, the circumstances being j ust the reverse of what he had 
supposed, the accommodation, the adaptation, the completeness 
and perfection of design for which he is arguing, imply not 
fixity of species but variation ? This or that minute organism 
may have survived all changes for an incalculable period. 
Dredging expeditions may bring up from the depths of the 
ocean forgotten forms of species supposed to have been long 
extinct ; but no researches will give us back in the clothing of 
flesh the gigantic mammals, birds, and lacertilians with whose 
fossil bones we are gradually becoming familiar under the awe- 
inspiring names of Palceotherium and Dinornis and Megalo - 
saurus. It is safe to affirm that the great Meiocene tortoise, 
Colossochelys Atlas , will crawl and creep never again in active 
existence. 
But, it may be argued, that power of migration which you 
speak of would have sufficed to preserve species from the effects 
of variation in climate and other conditions without varia- 
tion in the species themselves. It would help ; it is not true 
that it would suffice, because the power is limited. Some- 
thing more was required to maintain that wonderful diver- 
sity which we perceive both in the present and the past — 
plasticity, namely, in the species themselves. 
One of the grand arguments urged repeatedly against the 
variation of species is this — that no one has ever seen one species 
change into another ; that there is no known instance of such 
an occurrence. It is a wonderful argument, especially wonder- 
ful from the lips whence in general it proceeds — from lips ever 
prone to exalt the decisions of faith above the decisions of sight. 
By the same argument no man can believe in God, since no 
man has ever seen Him. The very same argument tells equally 
against what Sir Charles Bell calls distinct creation , since no 
man has ever seen a single instance of that method of pro- 
duction. 
To prove design in the works of Nature, Paley compared, 
as well as he might do, the construction and action of living 
organisms with the construction and action of machinery made 
by human art, especially one beautiful, ingenious, and well- 
known piece of machinery — a watch. He propounded further 
the conception of a watch 6C possessing the property of pro- 
ducing, in the course of its movement, another watch like itself,” 
inferring justly that the effect would be to increase an observer’s 
“ admiration of the contrivance, and his conviction of the con- 
