"If a man be blinded by accident or disease, his blindness is acquired. But if he comes into the world blind, if he be blind by nature, his blindness is inborn. If a son be naturally smaller than his father, then his inferiority of size is inborn; but if his growth be stunted by ill health or lack of nourishment or exercise, his inferiority is acquired.
"Lamarck held, as people in all ages have held, that characters acquired by parents are also transmissible to some extent, and that evolution results from their accentuation during succeeding generations. Lamarck's theory is rejected totally by the modern followers of Darwin.
"Ten thousand men might break their fingers, yet among their offspring not one might have a crooked finger. Consider on the other hand for how many generations women have bored their ears and noses in India. Yet when is a girl born with ears and nose already pierced? For how many generations have we amputated the tails of terriers, and yet their tails are no shorter. It will then be perceived how overwhelming is the case against the doctrine of the transmission of acquirements.
"The general question of the transmission of acquirements is too big and too abstruse to be treated adequately here. Two arguments more I may use, however, partly because they have not been developed, to my knowledge, by other writers, and partly because they seem to me well-nigh decisive. The more than normal development of the blacksmith's arm is rightfully called an acquired trait, since it arises from exercise, from use, not from germinal conditions. But no infant's arm develops into an ordinary adult arm without exercise similar in kind to that which develops the blacksmith's arm, though less in degree.
"Every single thing contained within the memory of man, every single word of a language, for instance, is an acquirement. But when are the contents of a parent's mind transmitted to the child?
"Again, a man is capable of becoming a parent at any time between extreme youth and extreme old age; a woman from the age of thirteen to fourteen till nearly fifty. Between the birth of the first child and the last such an individual changes vastly. Under stress and fear of circumstances, under the slings and arrows of outrageous fortune, all sorts of acquirements are made. The body becomes vigorous and then feeble, the mind grows mature, and then senile. He or she grows wrinkled and bowed and perhaps very wise, or perhaps much the reverse. Yet no one viewing a baby show, a children's party, or an assembly of adults, of whom he has no previous knowledge, can say which is the child of the youthful and which of aged parents.
"Apparently, therefore, the whole of the parent's acquirements have no effect on the child. Surely no evidence could be stronger."* [* The undoubted transmission of siphilis [tr. note: sic] to off-spring might be regarded as a case of transmission of an acquired characteristic. But the case is not in point since congenital siphilis [tr. note: sic] is, properly, due to a prenatal infection, the bacillus entering the very germ-plasm of the human ovum (egg). Medical science, generally, has become very cautious in the use of the word "hereditary." There is almost unanimity among medical men in the denial of heredity as a factor in tuberculosis and cancer. Most physicians are honest enough to say that they know considerably less about these things than was "known" ten and twenty years ago.]
Herbert Spencer claims that "the inheritance of acquired characters" is a necessary supplement to natural selection. "Close contemplation of the facts impresses me more strongly than ever with the two alternatives—either there has been inheritance of acquired characters, or there has been no evolution." Again, "the inheritance of acquired characters, which it is now the fashion of the biological world to deny, was by Mr. Darwin fully recognized and often insisted on." "The neo-Darwinists, however, do not admit this cause at all." He admits that known facts which show that acquired characters are inherited are few, but he thinks that they are "as large a number as can be expected, considering the difficulty of observing them and the absence of search." From the above, we see that the biological world is against Mr. Spencer's view; that he would abandon the theory of evolution unless acquired characters had been inherited, but that facts in support of this theory are meager. "Biologists in the above instance, as well as in others, differ in theory as to fundamental principles of evolution. He who imagines that the theory of organic evolution has been proved to the point of demonstration, has but to read the contentions of evolutionists themselves with regard to the most important things involved in the theory, in order to satisfy his mind that there is great diversity of opinion." (Fairhurst.)
The general abandonment of the Darwinian hypothesis by biologists, adverted to in our next chapter, is mainly due to the failure of heredity to account for the gradual modification of organs and of habits.
Various expedients are resorted to by Haeckel and a few others in their attempts to bolster up a theory which has broken so signally on the rock of heredity. Principal among these is the reference to unlimited time. It is asserted that, after all, such minute differences might, in the course of many ages, result in new and more perfect organs. However, here a new and unexpected difficulty presents itself. The physicist, who has measured the heat of the sun, rises up and says that the age of the earth, as estimated by specialists like Lord Kelvin, is not nearly so great as is demanded by the Darwinian. The period which the physicists, in their mercy, appear to be willing to grant the inhabitable globe is from twenty to forty million years. But the evolutionists maintain with great fervor that this period is far too short for the production of such complicated types of organism as now live on the earth; they demand from two hundred to a thousand million years! And so these two groups of scientists, the evolutionistic biologist and the physicists are hopelessly at odds.