3. Homologous anatomical structure is found to obtain very extensively among widely diverse races, _e. g._ in the arm of man, the fore-leg of the monkey and indeed of all quadrupeds, in the wing of the bird and the fin of the fish. This indicates a common parentage.
4. Some animals which, fully grown, differ from each other widely, are scarcely distinguishable in the embryo. Hence he infers their common origin.
5. The fact of rudimentary organs is assumed to be _historic_, proving that some ancient progenitor used them, and that they have gradually passed out of use. This is held to prove that great changes of structure come of genealogical descent.
1. To Darwin’s first law, viz. that the offspring always vary though slightly from the parent, and therefore, given indefinite time, he has any desired amount of variation, I reply that this law of variation becomes practically worthless for his theory, because these variations from parent to offspring run in all conceivable directions and not in the one definite direction required for his purpose, _i. e._ toward a higher grade of perfection, or [which his argument requires] toward a new form of animal life. For example, there is always some change in the human countenance from parent to child. Yet who does not know that those changes run in every possible direction and not in one uniform line of progress or advance, as from monkey toward man and from man toward angel? For another example we may take the shape of the skull and of the brain――evermore differing slightly from parent to offspring yet not by any means on one given line. The skulls of Egyptian mummies entombed three thousand years ago do not differ appreciably from those of the Copts (their lineal descendants) of to-day, _i. e._ are no more pithecoid――ape-like. On Darwin’s theory three thousand years backward ought surely to approximate toward the ape; otherwise these variations are fruitless. This law of successive genealogical changes amounts to nothing for his argument unless the changes consent to _come into line_ so that their results shall actually _accumulate_ with the lapse of ages. The fatal lack in the argument is――no husbandry of these infinitesimal changes――not the least perceivable accumulation.