A History of Science — Volume 5

by Henry Smith Williams; Edward Huntington Williams

It was no great thing to discover this paucity, which, indeed, fairly beckoned the discoverer. The great thing was to supply the deficiency, and this was what Dr. Dohrn determined to do. He selected Naples as the best location for the laboratory he proposed to found, because of its climate and its location beside the teeming waters of the Mediterranean. He organized a laboratory; he called about him a corps of able assistants; he made the Marine Biological Laboratory at Naples famous, the Mecca of all biological eyes throughout the world. It was not all done in a day. It was far enough from being done without opposition and discouragement; but these are matters of history which Dr. Dohrn now prefers not to dwell upon. Suffice it that the result aimed at was finally achieved, and in far greater measure than could at first be hoped for.

And from that day till this Naples has been the centre of that branch of biological inquiry which has for its object the investigation of problems best studied with material gathered from the sea. And this, let me hasten to add, includes far more than a mere study of the life histories of marine animals and plants as such. It includes problems of cell activity, problems of heredity, life problems of many kinds, having far wider horizons than the mere question as to how a certain fish or crustacean lives and moves and has its being.

Dr. Dohrn's chief technical associates are all Germans, like their leader, but, like him also, all gifted with a polyglot mastery of tongues that has stood them in good stead in their intercourse with the biologists of many nationalities who came to work at the laboratory. I must not pause to dwell upon the personnel of the staff in general, but there is one other member who cannot be overlooked even in the most casual survey of the work of the institution. One might almost as well forget Dr. Dohrn himself as to overlook Signor Lo Bianco, chief of the collecting department. Signor Bianco it is who, having expert knowledge of the haunts and habits of every manner of marine creature, can direct his fishermen where to find and how to secure whatever rare specimen any worker at the laboratory may desire. He it is, too, who, by studying old methods and inventing new ones, has learned how to preserve the delicate forms for subsequent study in lifelike ensemble that no one else can quite equal. Signor Bianco it is, in short, who is the indispensable right-hand man of the institution in all that pertains to its practical working outside the range of the microscope. Each night Signor Lo Bianco directs his band of fishermen as to what particular specimens are most to be sought after next day to meet the needs of the workers in the laboratory. Before sunrise each day, weather permitting, the little scattered fleet of boats is far out on the Bay of Naples; for the surface collecting, which furnishes a large share of the best material, can be done only at dawn, as the greater part of the creatures thus secured sink into the retirement of the depths during the day, coming to the surface to feed only at night. You are not likely to see the collecting party start out, therefore, but if you choose you may see them return about nine or ten o'clock by going to the dock not far from the laboratory. The boats come in singly at about this hour, their occupants standing up to row, and pushing forward with the oars, after the awkward Neapolitan fashion. Many of the fishermen are quaint enough in appearance; some of them have grown old in the service of the laboratory. The morning's catch is contained in glass jars placed in baskets especially constructed for the purpose. The baskets have handles, but these are quite superfluous except to lift them from the boats, for in the transit to the laboratory the baskets are carried, as almost everything else is carried in Naples, on the head. To the novitiate it seems a striking risk to pile baskets of fragile glass and even more fragile specimens one above another, and attempt to balance the whole on the head, but nothing could be easier, or seemingly more secure, for these experts. Arrived at the laboratory, the jars are turned over to Signer Lo Bianco and his assistants, who sort the material, and send to each investigator in the workrooms whatever he may have asked for.

Of course surface-skimming is not the only method of securing material for the laboratory. The institution owns a steam-launch named the Johannes Müller, in honor of the great physiologist, which operates a powerful dredge for securing all manner of specimens from the sea-bottom. Then ordinary lines and nets are more or less in requisition for capturing fish. And in addition to the regular corps of collectors, every fisherman of the neighborhood has long since learned to bring to the laboratory all rare specimens of any kind that he may chance to capture. So in one way and another the institution makes sure of having in tribute all that the richly peopled waters of the Mediterranean can offer. And this well-regulated system of collecting, combined with the richness of the fauna and flora of the Bay of Naples, has no small share in the success of the marine laboratory. But these, of course, were factors that Dr. Dohrn took into account from the beginning.

Indeed, it was precisely with an eye to these important factors that Naples was selected as the site of the future laboratory in the days when the project was forming.

The Bay of Naples is most happily located for the needs of the zoologist. It is not too far south to exclude the fauna of the temperate zone, yet far enough south to furnish a habitat for many forms of life almost tropical in character. It has, in short, a most varied and abundant fauna. And, on the other hand, the large colony of Neapolitan fishermen made it certain that skilled collectors would always be at hand to make available the wealth of material. It requires no technical education to appreciate the value of this to the original investigator, particularly to the student of life problems. A skilful worker may do much with a single specimen, as, for example, Johannes Mûller did half a century ago with the one available specimen of amphioxus, the lowest of vertebrates, then recently discovered. What Mûller learned from that one specimen seems almost miraculous. But what if he had had a bucketful of the little boneless creatures at his disposal, as the worker at Naples now may have any day for the asking?

When it comes to problems of development, of heredity, a profusion of material is almost a necessity. But here the creatures of the sea respond to the call with amazing proficiency. Most of them are, of course, oviparous, and it is quite the rule for them to deposit their eggs by hundreds of thousands, by millions even. Everybody knows, since Darwin taught us, that the average number of offspring of any given species of animal or plant bears an inverse proportion to the liability of that species to juvenile fatalities. When, therefore, we find a fish or a lobster or other pelagic creature depositing innumerable eggs, we may feel perfectly sure that the vast majority of the eggs themselves, or the callow creatures that come out of them, will furnish food for their neighbors at an early day. It is an unkind world into which the resident of the deep is born. But his adversity is his human contemporary's gain, and the biologist will hardly be blamed, even by the most tender-hearted anti-vivisectionist, for availing himself freely of material which otherwise would probably serve no better purpose than to appease the appetite of some rapacious fish.

Their abundance is not the only merit, however, of the eggs of pelagic creatures, in the eyes of the biologist. By equal good-fortune it chances that colorless things are at a premium in the sea, since to escape the eye of your enemy is a prime consideration. So the eggs in question are usually transparent, and thus, shielded from the vision of marine enemies, are beautifully adapted for the observation of the biologist. As a final merit, they are mostly of convenient size for manipulation under the microscope. For many reasons, then, the marine egg offers incomparable advantages to the student of cell life, an egg being the typical cell. And since nowadays the cell is the very focus of attention in the biological world, the importance of marine laboratories has been enhanced proportionately.

But of course not all the work can be done with eggs or with living specimens of any kind. It is equally important on occasion to examine the tissues of adult specimens, and for this, as a rule, the tissues must first be subjected to some preserving and hardening process preliminary to the cutting of sections for microscopical examination. This is done simply enough in the case of some organisms, but there is a large class of filmy, tenuous, fragile creatures in the sea population of which the jellyfish may be mentioned as familiar examples. Such creatures, when treated in an ordinary way, by dropping them into alcohol, shrivel up, coming to resemble nothing in particular, and ceasing to have any value for the study of normal structures. How to overcome this difficulty was one of the problems attacked from the beginning at the Naples laboratory. The chief part of the practical work of these experiments fell to the share of Signor Lo Bianco. The success that attended his efforts is remarkable. To-day you may see at the laboratory all manner of filmy, diaphanous creatures preserved in alcohol, retaining every jot of their natural contour, and thus offering unexampled opportunities for study en masse, or for being sectioned for the microscope. The methods by which this surprising result has been accomplished are naturally different for different creatures; Signor Lo Bianco has written a book telling how it all has been done. Perhaps the most important principle involved with a majority of the more tenuous forms is to stupefy the animal by gradually adding small quantities of a drug, such as chloral, to the water in which the creature is detained. When by this means the animal has been rendered so insensible that it responds very sluggishly to stimuli, it is plunged into a toxic solution, usually formaline, which kills it so suddenly that its muscles in their benumbed state have not time to contract.

Any one who has ever tried to preserve a jellyfish, for example, by ordinary methods will recall the sorry result, and be prepared to appreciate Signor Lo Bianco's wonderfully beautiful specimens. Naturalists have come from all over the world to Naples to learn "just how" the miracle is accomplished, for it must be understood that the mere citation of the modus operandi by no means enables the novitiate to apply it successfully at once. In the case of some of the long-drawn-out forms of clustered ascidians and the like, the delicacy of manipulation required to make successful preservations raises the method as practised at Naples almost to the level of a fine art. It is a boon to naturalists everywhere that the institution here is able sometimes to supply other laboratories less favorably situated with duplicates from its wealth of beautifully preserved specimens.