CHAPTER IV
SOME BIOLOGICAL QUESTIONS IN DACTYLOGRAPHY.
In this chapter I propose to bring together a few important points of a biological character, which are so vital that even in so curtailed a discussion they cannot be ignored. We shall also glance—it must literally be the merest glance—at the problem of man’s genetic descent, in so far as it begins now to be illumined, however faintly, by a comparative study of finger-prints. Comparatively little of a final character has as yet been achieved, but there are now not a few active and intelligent observers in many lands, and the scientific results often attained under the greatest difficulties are so far greatly encouraging. Fortunately the day has long passed away when it can be considered irreverent to enquire modestly as to who were one’s ancestors. In a very true biological sense every human individual is known to have run through a scale of existence, beginning from the lowest mono-cellular organism, through something like a tadpole or salamander, into a vertebrate and mammal type, not easily to be discriminated from the undeveloped young of rat, or pig, or monkey. Now, if he is not in any way individually degraded by this actually demonstrable course of development, why should he be thought racially degraded by an honest scientific effort to trace the origin of his species from lowly animal ancestry? The process may be slower, but is no less determined by divinely established law. Our grandfathers believed that the Creator breathed into the organized and shapely form of Adam (= “a man”) a portion of the divine spirit, by which he became a living soul, and forthwith took his dignified place in nature. To me the old story, when retold in more modern and exact phrase, leads us to an entirely hopeful and inspiring conception of the origin and evolutionary destiny of our race.
When we approach the threshold of man’s first appearance on the globe, we have reached a geologic epoch when our sober earth seems to have sown most of its wild oats. Its “crust” is pretty stable, and at least in its broad distribution of sea and land, it does not seem to differ very greatly from what its appearance presents on a modern physiographical map. Minor differences there must have been, as even our modern English coast-line shows, and there may have been other conditions than now exist to account for many of man’s early migrations, but those differences are still matters of discussion. There were, possibly, enough certain bridge-like links between lands now apart and separated by wide stretches of sea, but, as a rule, such conclusions have been deductively reached, and are not definitely established on scientific evidence.
After rising above one-celled to more complicated organisms, we reach a class of creatures in which a radiate or wheel-like form obtains, that is, radial symmetry, as in jelly-fish, star-fish, urchins, and sea-anemones.
Fishes occupy, perhaps, about the lowest level among the back-boned or vertebrate animals, and we may readily notice that some of their fins occur in symmetrically arranged pairs, while others, again, occur singly. Now with this arrangement of such appendages in pairs symmetrically arranged there begins the appearance of something definitely like what we mean by limbs. Some present-day fishes use some of their fins as legs to clamber and crawl on rocks or ashore. I remember seeing, in a Japanese tea-house by the solitary sea-shore, not far from where the great arsenal of Yokoska now hums busily, a very beautiful gurnard, blue as to its outspread wings like the sapphire gurnard. Those fins were painted like the wings of a butterfly, and it crawled about in the limited sea-water, on rocks, under cliffs, and among sea-weed, with butterfly-like legs or processes from the roots of those wing-like fins. With such a special adaptation of their fins, fishes began to conquer the land. Seals and whales, as is well known, are mammals which have been driven back again to the sea.
Thesing, in his suggestive Lectures on Biology (English translation, p. 13), says:—
“All extremities of the higher vertebrates, however widely they may differ in construction, may be traced back biogenetically to the so-called Ichthyopterygium, as we see it in the lower shark-like fishes. Unequal growth of the single skeleton parts and a considerable reduction in their numbers transformed the Ichthyopterygium into the five-fingered extremity characteristic of all vertebrates from the amphibians upwards.”
Anthropoid Lineations.