It is not impossible that the key to the more specific problem may fit the lock which seals the greater.

In the second place, the two subjects are historically associated. So long as men believed that species are distinct creations, no philosophy of evolution could have gained general acceptance. By convincing all thoughtful persons that species have a history which may be studied by scientific methods, Darwin led many who would not otherwise have given it a hearing, to treat the new philosophy with respect: but natural science is not "philosophy," notwithstanding this intimate historical connection between the proof that species are mutable and the spread of belief in the Philosophy of Evolution." I have selected the passage which I have put at the head of this chapter in order to show that the view of the matter which is here set forth is not new, even among advanced biologists.

Huxley's attitude will, no doubt, be a surprise to many who think they have read his books with diligence. He continually calls himself an "Evolutionist," and he can hardly blame a reader who, failing to draw nice distinctions, holds him to be one of the chief pillars in the temple of the new philosophy. Some confusion may be permitted to those who remember his public lectures on "Evolution," his essays with the same title, and his declaration that the work of his life has involved him "in an endless series of battles and skirmishes over evolution."

It is easy for one who understands his true position to see that his essays lend no countenance to the opinion that he has ever been or sought to be either a pillar or a disciple of any system of philosophy; for he has never ceased from affirming his ignorance of many of the subjects which philosophy seeks to handle.

His evolution is not a system of philosophy, but part of the system of science. It deals with history with the phenomenal world and not with the question what may or may not lie

behind it.

During the last half-century natural science has become historical. We have opened and learned to read a new chapter in the records of the past. The attributes of living things, which seemed to the older naturalists to be complete and independent

in themselves, have proved to have a history which can be studied by the methods of science. They have been found to be steps in a long sequence of events as orderly and discoverable as the events. which are studied by the astronomer or the geologist.

The cultivation of natural science in this historical field, and the discovery that the present order of living things, including conscious, thinking, ethical man, has followed after an older and simpler state of nature, is not "philosophy," but science. It involves no more belief in the teachings of any system of philosophy than does the knowledge that we are the children of our parents and the parents of our children; but it is what Huxley means by "evolution."

"1

His lectures on "Evolution" deal with paleontology, and narrate facts which are found in every text-book on the subject; but natural science, as it is taught in the text-books on botany and zoology and embryology and paleontology, is, most assuredly, no "Philosophy of Evolution." It fell to Huxley to fight and win a battle for science; and while he himself calls it a battle for evolution, his use of the word need mislead none, although it has misled many.

One word in its time plays many parts, and the word " 'evolution" has had many meanings. To-day, in popular estimation, an evolutionist is not a follower of Bonnet; nor one who is occupied with the binomial theorem, or with the evolutions of fleets and armies. Neither is he a cultivator of natural science. Whatever the word may have meant in the past, it has, in common speech, come to mean a believer in that philosophy of evolution which, according to such evolutionists as Huxley, is "premature." Since this is so, and since the growth of language is beyond individual control, would it not be well for those who stand where Huxley stands, and "have nothing to say to any philosophy of evolution," to stop calling themselves "Evolutionists," and to be content with the good old name of "Naturalist"?

To the pious evolutionist, who asks what will become of the fixed order of nature if we are not convinced that everything is determinate, we answer that, while this sort of reasoning is not new, it has a strange sound in the mouth of a student of science.

1 See Huxley," Essays," V. i., pp. 44-54.

The order of nature has outlasted many systems of philosophy, and it may survive others. We have found our astronomy and our geology and our law of the mutability of species, and none of the dreadful things predicted by "philosophers" have come about. There may still be more things in heaven and earth than are dreamed of in "philosophy."

History warns us that, as the price of progress in science, all the idols of the theatre, and all other idols, "must be abjured and renounced with firm and solemn resolution, and the understanding must be completely freed and cleared of them; so that the access to the kingdom of man, which is founded on the sciences, may resemble that to the kingdom of heaven, where no admission is conceded except to children."

If the world thinks hard names are the just due of them who assert their living wish to know, while humbly confessing ignorance, the biologist must bear up as well as he can if he is called a "scientific Rip Van Winkle," or an "agnostic," or even "a malignant and a turban'd Turk."

If we seek admission to the temple of natural knowledge naked and not ashamed, like little children, hard names cannot hurt us, nor need they scare us.

LECTURE VI-PART II

A NOTE ON THE VIEWS OF GALTON AND WEISMANN ON

INHERITANCE

Two of the most prominent writers on inheritance, Weismann and Galton, base their views of variation on the assumption that at each remote generation, the ancestors of a modern organism were innumerable, although a little reflection will show that this assumption is quite untenable.

Weismann, in his earlier writings at least, finds the "cause of variation" in the recombination, by sexual reproduction, of the effects of the diversified influences which acted upon the innumerable protozoic ancestors of each modern metazoön; but this opinion deserves little consideration, as a contribution to our knowledge of inheritance, if we can prove that these protozoic ancestors must have been very few, and if we can also prove that, if these few were ancestors of any modern metazoön, they must have been the common ancestors of all the modern metazoa.

Galton's view of the diversity among individuals is much like Weismann's. He says: "It is not possible that more than onehalf of the varieties and number of the parental elements, latent or potential, can on the average subsist in the offspring. For if every variety contributed its representatives, each child would on the average contain, actually or potentially, twice the variety and twice the number of elements, whatever they may be, that were possessed at the same stage of its life by either of its parents, four times as many as any of its grandparents, 1024 times as many as any of its ancestors of the tenth degree, and so on."

As he holds that each offspring must therefore get rid, in some way, of half the variety transmitted from its ancestors, he finds an explanation of the diversity between individuals in the diversity of the retained halves of their variety.

Each person has two parents, and four grandparents; but even in a country like ours, which draws its people from all quarters of the earth, each of the eight great-grandparents is not always a distinct person; for when the parents are cousins, this number is six, or five, or even four, instead of eight. Among more primitive folks, who stay at home generation after generation, and marry neighbors, a person whose ancestors have transgressed none of our social laws may have a minimum ancestry of only four in each generation. The maximum and the minimum fixed by our customs are given, for ten generations, in the two lines below:

Few persons who can trace their ancestry for ten generations with completeness are descended from 1024 distinct persons in the tenth generation; and in all old stable communities of simple folks the number is very much smaller. In the long run, the number of ancestors in each generation is determined by the average sexual environment, and it must be a small and pretty constant number.

All genealogical study gives indirect evidence of this familiar fact, which has not been adequately recognized by students of inheritance. I have made a computation from the genealogical history of the people of a small island on our coast. These people lead a simple life, or at least they have done so in the past; but most of the men have been sailors, and have ranged much farther in search of mates than agricultural people. I have selected three persons whose ancestry is recorded in detail for some seven or eight generations. These three persons would not be popularly regarded as near relations, for they have no parents or grandparents with like names, although two of the grandparents were cousins. The generations are not quite parallel, for the period covered by eight in one line is covered by seven in the two others, and the average is about seven and a half.

In seven and a half generations the maximum ancestry for one person is 382, or, for three persons, 1146. The names of 452 of them, or nearly half, are recorded, and these 452 named ancestors