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.