The Relation of Science and Religion.pdf - Online Christian Library

APPENDIX. 317observers admit that they are perplexed by facts ascertained,and confess that they can not as yet offer anexplanation. To others all is as plain as possible; embryologysupplies a convincing proof of the accuracyof an evolution theory; but these are scientific theoristswho see by imagination, and are impatient of uncertainty.There are certain general considerationswhich must interpose difficulties in the way of constructingan argument from Embryology to evolutionof species. (1) The action of environment before birthis altogether different from the action of environmentafter birth. (2) The theory of the evolution of speciesemphasizes this difference by insisting on the strugglefor existence. (3) This difference being admitted, anargument from the one to the other can not hold. Inthe line of discovery the point of chief interest hasbeen the fact that in some cases embryonic life showsa transition through lower forms analogous to lowerorders of animal existence prior to reaching the maturestage when birth occurs. But in connection withthe facts ascertained, two things are to be remarked.(1) Evidence of transitioll is most striking in the historyof animal life developed external to the parentallife, as in the transition from laruce to pupce among insects,and in the changes in the life of the tadpole.(2) If it be admitted that there is a common plan ofstructure for all organism, it is implied that there mustbe similarities in process of development. The questionrequiring answer, therefore, is whether in thegradual development from the germ, any further resemblanceto lower orders appears than is to be anticipatedon the admission of a common plan for organic