A History of Science — Volume 5

by Henry Smith Williams; Edward Huntington Williams

METHODS AND RESULTS

These, then, are some of the material conditions that have contributed to make the results of the scientific investigations at the Naples laboratory notable. But of course, even with a superabundance of material, discoveries do not make themselves. "Who uses this material?" is, after all, the vital question. And in this regard the laboratory at Naples presents, for any one who gets at its heart, so to speak, an ensemble that is distinctive enough; for the men who work in the light and airy rooms of the laboratory proper have come for the purpose from all corners of the civilized globe, and not a few of them are men of the highest distinction in their various lines of biological science. A large proportion are professors in colleges and universities of their various countries; and for the rest there is scarcely one who is not in some sense master of the biological craft. For it must be understood that this laboratory at Naples is not intended as a training-school for the apprentice. It offers in the widest sense a university course in biology, and that alone. There is no instructor here who shows the new-comer how to use the microscope, how to utilize the material, how to go about the business of discovery. The worker who comes to Naples is supposed to have learned all these things long before. He is merely asked, then, what class of material he desires, and, this being furnished him, he is permitted to go his own way unmolested. He may work much or little, or not at all; he may make epochal discoveries or no discoveries of any sort, and it will be all one to the management. No one will ask him, in any event, what he has done or why he has not done otherwise. In a word, the worker in the laboratory here, while being supplied with opportunities for study such as he could hardly find elsewhere, retains all the freedom of his own private laboratory.

Little wonder, then, that it is regarded as a rare privilege to be allowed to work in this laboratory. Fortunately, however, it is a privilege that may be obtained by almost any earnest worker who, having learned the technique of the craft elsewhere, desires now to prosecute special original studies in biology. Most of the tables here are leased in perpetuity, for a fixed sum per annum, by various public or private institutions of different countries. Thus, for example, America has the right of use of several tables, the Smithsonian Institution leasing one, Columbia University another, a woman's league a third, and so on. Any American desiring to work at Naples should make application to one of these various sources, stating the exact time when he would like to go, and if there be a vacancy for that time the properly accredited applicant is almost sure to receive the privilege he asks for. Failing in this, however, there is still a court of last appeal in Dr. Dohrn himself, who may have a few unoccupied tables at his disposal, and who will surely extend the courtesy of their occupancy, for a reasonable period, to any proper applicant, come he whence he may.

Thus it chances that one finds men of all nations working in the Naples laboratory—biologists from all over Europe, including Russia, from America, from Australia, from Japan. One finds women also, but these, I believe, are usually from America. Biologists who at home are at the head of fully equipped laboratories come here to profit by the wealth of material, as well as to keep an eye upon the newest methods of their craft, and to gain the inspiration of contact with other workers in allied fields. Many of the German university teachers, for example, make regular pilgrimages to Naples during their vacations, and more than one of them have made the original investigations here that have given them an international reputation.

As to the exact methods of study employed by the individual workers here, little need be said. In this regard, as in regard to instrumental equipment, one biological laboratory is necessarily much like another, and the general conditions of original scientific experiment are pretty much the same everywhere. What is needed is, first, an appreciation of the logical bearings of the problem to be solved; and, secondly, the skill and patience to carry out long lines of experiments, many of which necessarily lead to no tangible result. The selection of material for the experiments planned, the watching and cultivating of the living forms in the laboratory tanks, the cutting of numberless filmy sections for microscopical examination—these things, variously modified for each case, make up the work of the laboratory student of general biology. And just in proportion as the experiments are logically planned and carefully executed will the results be valuable, even though they be but negative. Just in proportion as the worker, by inclusion and exclusion, attains authentic results—results that will bear the test of repetition—does his reputation as a dependable working biologist become established.

The subjects attacked in the marine laboratory first and last are practically coextensive with the range of general biology, bacteriology excepted. Naturally enough, the life histories of marine forms of animals and plants have come in for a full share of attention. But, as I have already intimated, this zoological work forms only a small part of the investigations undertaken here, for in the main the workers prefer to attack those general biological problems which in their broader outlines apply to all forms of living beings, from highest to lowest. For example, Dr. Driesch, the well-known Leipzig biologist, spends several months of each year at the laboratory, and has made here most of those studies of cell activities with which his name is associated. The past season he has studied an interesting and important problem of heredity, endeavoring to ascertain the respective shares of the male and female parents in the development of the offspring. The subjects of his experiments have been various species of sea-urchins, but the principles discovered will doubtless be found to apply to most, or perhaps all, forms of vertebrate life as well.

While these studies were under way another developmental problem was being attacked in a neighboring room of the laboratory by Professor Kitasato, of the University of Tokio, Japan. The subjects this time were the embryos of certain fishes, and the investigation had to do with the development of instructive monstrosities through carefully designed series of injuries inflicted upon the embryo at various stages of its development. Meantime another stage of the developmental history of organic things—this time a microscopical detail regarding the cell divisions of certain plants—has been studied by Professor Mottier, of Indiana; while another American botanist, Professor Swingle, of the Smithsonian Institution, has been going so far afield from marine subjects as to investigate the very practical subject of the fertilization of figs as practised by the agriculturists about Naples.

Even from these few citations it will appear how varied are the lines of attack of a single biological problem; for here we see, at the hands of a few workers, a great variety of forms of life—radiates, insects, vertebrates, low marine plants and high terrestrial ones—made to contribute to the elucidation of various phases of one general topic, the all-important subject of heredity. All these studies are conducted in absolute independence, and to casual inspection they might seem to have little affinity with one another; yet in reality they all trench upon the same territory, and each in its own way tends to throw light upon a topic which, in some of its phases, is of the utmost practical importance to the human family. It is a long vault from the embryo of an obscure sea-weed to the well-being of man, yet it may well happen—so wide in their application are the general life principles—that study of the one may point a practical moral for the other.

Indeed, it constantly happens that the student of biology, while gazing through his microscope, hits upon discoveries that have the most far-removed implications. Thus a few years ago it was discovered that when a cell is about to bisect itself and become two cells, its nucleus undergoes a curious transformation. Within the nuclear substance little bodies are developed, usually threadlike in form, which take on a deep stain, and which the biologist calls chromosomes. These chromosomes vary in number in the cells of different animals, but the number is always the same for any given species of animal. If one were to group animate beings in classes according to this very fundamental quality of the cells he would have some very curious relations established. Thus, under the heading "creatures whose cells have twenty-four chromosomes," one would find beings so different as "the mouse, the salamander, the trout, and the lily," while the sixteen-chromosome group would introduce the very startling association of the ox, the guinea-pig, the onion, and man himself. But whatever their number, the chromosomes are always exactly bisected before the cell divides, one-half being apportioned to each of the two cells resulting from the division.

Now the application is this: It was the study of these odd nuclear structures and their peculiar manouvrings that, in large measure, led Professor Weismann to his well-known theory of heredity, according to which the acquired traits of any being are not transmissible to the offspring. Professor Weismann came to believe that the apportionment of the nuclear substance, though quantitatively impartial, is sometimes radically uneven in quality; in particular, that the first bisection of the egg-cell, which marks the beginning of embryonic development, produces two cells utterly different in potentiality, the one containing the "body plasm," which is to develop the main animal structures, the other encompassing the "germ plasm," by which the racial integrity is [to be preserved. Throughout the life of the individual, he believed, this isolation continued; hence the assumed lack of influence of acquired bodily traits upon the germ plasm and its engendered offspring. Hence, also, the application of the microscopical discovery to the deepest questions of human social evolution.