The Depths of the Ocean

THE title of a book sometimes is, and always should be, descriptive of its contents. Dr. Agassiz’s book 1 has two titles, but both are singularly inadequate; a reader not familiar with the history of the investigations which it records must needs explore the introductions and table of contents to learn the extent of its scope. The principal title scarcely covers the two opening chapters, and the subordinate title is also far too modest, since the author has presented a comprehensive treatise upon the whole science of thalassography, rather than a “ contribution ” restricted to the consideration of it in its American aspects. This manner of choosing a title is not without precedent. Professor Huxley made his treatise on The Crayfish broad enough to cover the whole field of biology. This, however, was a book for elementary students, and its name was not seriously misleading. The standard English works upon the same subject carry such general titles as The Depths of the Sea and Thalassa, and one cannot help regretting that the broader and more scholarly American treatise should have a name so much less comprehensive.

The Blake, it should he explained, is a small steamer belonging to the United States Coast Survey, which has been employed in hydrographic work ever since 1874 ; it has done much excellent service in deep-sea sounding, under the direction of such accomplished naval officers as Sigsbee and Bartlett, who have also made most important studies upon the phenomena of the Gulf Stream. On three occasions, between 1877 and 1880, this vessel was especially detailed for the study of the organisms which live in the oceanic abysses, and the peculiarities of their environment.

The Agassizs, father and son, have been closely associated with the scientific work of the Coast Survey for the past forty years, and it was in recognition of this fact, and of the eminence of Mr. Alexander Agassiz as an authority upon ocean physics, that the position of superintendent of the Survey was offered him, not long ago, by the President. As early as 1849, Louis Agassiz, with his son as an assistant, made a cruise of investigation in the Bibb, the predecessor of the Blake ; and later, personally and by his friend and pupil the Count Pourtalès, who was an official of the Survey, and who was the pioneer of deep-sea dredging in America, a constant series of natural-history inquiries was kept up in connection with the work of the Survey.

In 1877 Mr. Alexander Agassiz was requested by Captain Patterson, the superintendent of the Coast Survey, to continue these biological studies, and in the three cruises of the Blake, referred to in the title of his book, he applied himself to the solution of a series of problems, the importance of which has for twenty-five years or more been constantly increasing in the estimation of men of science,—problems which have an essential bearing upon every department of thought, though most directly upon geology and meteorology, and upon philosophic biology, intimately associated as they are with all discussion of the development and geographical distribution of living forms.

The studies of forty years on the part of the Agassizs, Pourtalès, and their associates, as well as those of the Coast Survey officials engaged in the explorations of the Atlantic basin from other points of view, have culminated in this book ; for although many thousands of pages have been printed, giving preliminary and detailed reports of exploration, no effort has hitherto been made to combine the results for the purposes of philosophic discussion. Indeed, many of the facts observed in the earlier days have been, until recently, without meaning. The science of " thalassography ” was without a name, until, for use in the present treatise, its author constructed this word, which is defined as “ the science which treats of oceanic basins.”

The problems were fully outlined in the mind of the author before he attempted to study them with the aid of that most complicated and costly of modern scientific instruments, a sea-going steamer equipped for deep-sea research. They are stated in full in the first volume.

The first and most inviting of these problems was, of course, the topography of the eastern coast of the North American continent in relation to its fauna and flora. So thoroughly have the sounding-line and the dredge been plied along our entire coast within the past twenty years that it has been possible to construct a relief map of the continent slope, extending to mid-ocean depths four and five miles below the surface of the Atlantic, the valleys and mountain tops under the waters being as accurately defined as those of the Appalachians. As the geographer delights to name the highest peaks after distinguished explorers, so does the thalassographer associate the names of his heroes with the deepest valleys under the sea: such monuments are dedicated to the names of Sigsbee, Bartlett, and Pourtalès. All these features of the earth’s surface, until lately hidden from the comprehension of man, are described and graphically illustrated in a manner never before even attempted, and in a specially effective way, by an engraving of a relief model of a portion of the western North Atlantic.

In this connection, but rather in the form of an excursus, is presented an essay upon the Florida reefs, in relation to their origin and the general structure of the continent. The subject of atoll formation, for the explanation of which the theories of Darwin and Dana have so long been considered adequate, but which has of late come so prominently into view through the discussions of Semper and Murray and the allusions of the Duke of Argyll, is reviewed impartially. The descriptions of the reefs, and the life upon them and around them, are admirably written and illustrated. This chapter is especially interesting from the fact that the Agassizs have made the geology of this region peculiarly their own, and have accumulated such extensive collections from the reefs in the museum at Cambridge.

The essay on the permanence of continents and ocean basins is a natural outgrowth of those which it follows. It is full of suggestive thought and observation.

Theorizing upon the effect of the grinding action of the Gulf Stream upon the edge of the continent, the author estimates that a period of five millions of years has elapsed since the beginning of the tertiary period, and fifty millions of years since the first appearance of life upon the globe.

With the contours of the partially submerged region east of the Atlantic coast line in view, the mind naturally passes to the consideration of the relations of the flora and fauna of the West India Islands to those of the adjacent continent. This is a subject specially inviting to any one who has become interested in the essays already referred to, since its study may throw light upon the history of the formation of the continental outlines. In the essay upon this topic, as indeed in the whole work, theory is never confounded with fact, nor is it usually coupled closely with fact. The phenomena observed are stated in such a way that they invite the reader to make his own theories. The suggestiveness of the book is one main source of its interest. In this chapter, for instance, it is hinted that the island of Jamaica may at one time have been the northern spit of a gigantic promontory stretching out from a great island, within whose bounds were embraced Hayti, Porto Rico, and the Virgin Islands, and that the Caribbean Sea was a gulf of the Pacific, while Central America and northern South America were a series of large islands.

The nature of the formations at the bottom of the ocean is considered in the essays on Submarine Deposits and DeepSea Formations, and the reader learns how, by the aid of deep-sea apparatus, the modern geologists study in actual working the modes in which were deposited the marine strata of former geological periods, like those of the chalk, the oölite, and the miocene.

The essays on Temperatures of the Caribbean, Gulf of Mexico, and Western Atlantic and on The Gulf Stream are chiefly descriptive, and give a very excellent idea of the thermic conditions of these waters, and the depth and relative position of the temperature strata from surface to abyss. These matters are made very intelligible by the free use of diagrams, and admirably supplement the other essays. The history of Gulf Stream theory is given from the days of Kircher and Franklin, whose archaic maps are reproduced in fac-simile, to the most recent work, that of Commander Bartlett, who estimates that its delivery of heated water through the Straits of Florida is 872,000,000,000,000,000 pounds, or four hundred and thirty-six millions of millions of tons each day.

The second volume, though essential to the completeness of the work, is less interesting to readers of every class than the first. For the zoölogist it is too brief: he will prefer to consult the reports of the specialists, already published in a long series of the bulletins of the Museum of Comparative Zoölogy, where thousands of pages are devoted to what is here condensed within the limits of one hundred and fifty. The non-professional reader will find the text too technical, just as he did when he looked over Sir Wyville Thomson’s Voyage of the Challenger, ten years ago ; but he will derive abundant satisfaction from the engravings, which depict over three hundred of the most characteristic inhabitants of the ocean depths.

The chapter on the West Indian Fauna, in which the relations of the life of the shallow waters of this region to that of the adjacent abysses are discussed, will interest every one, since it renders evident the intimate connection between the animals living along our shores, near the surface, and those which have found their way into the deeper parts of the oceanic basins.

Three chapters in the first volume have especial connection with the contents of the second. That upon The Pelagic Fauna and Flora, which tells of the Sargasso Sea, and the curious animals which live in the floating masess of gulf-weed, and describes the other curious forms which live suspended in a thin stratum of surface-water, miles, it may be, from the ocean’s bottom below, and at practically insuperable distances from the shore, will bring old friends to the memory of every one who has passed many days at sea. The essay upon The Physiology of Deep Sea Life is overpowering in its suggestions of how little is really known, after all, of the regions described by the author. That upon The Deep Sea Fauna, on the other hand, gives a most impressive idea of the immensity of the work which has been accomplished within the last few years, — an impression which is intensified by reading what is said in the Historical Sketch of Deep Sea Work. We have merely skimmed the surface thus far, and have only traced a few thin lines with the dredge and trawl over the bottom of the oceans.”writes Agassiz ; and yet many new faunas have been discovered and partially explored, the inhabitants of which differ far more from those of the surface faunæ than the latter do from each other.

The writer of this review well remembers the day, only eleven years ago, when he saw dredged at a depth of one hundred and sixty fathoms, in the Gulf of Maine, two new species of deep-sea fishes, the first ever obtained by an American naturalist from the abyssal fauna along the coast. Since then, from these waters alone, by the efforts of the Blake, the Albatross, and the Fish Hawk, more new fishes have been discovered than were brought back from the three years’ cruise of the Challenger.

The most striking characteristic of Mr. Agassiz’s style is its compactness, and the impression which it gives of great reserves of unwritten knowledge. The reader feels that every chapter might have been readily expanded into a volume ; or it may be that the manuscript for a volume has actually been condensed within the limits of a chapter. It is possible that this condensation may interfere with the popularity of the book among general readers.

The tendency to specialization in scientific research is increasing each year, and the inevitable and proper result of this specialization is a marked increase in thoroughness of method and minute scrutiny of detail. The biologist of today gives as much time to the study of a single species as his predecessor of thirty years ago gave to an entire fauna.

The language of science shows a tendency to divide into dialects, and a corresponding specialization of habits of thought seems to be arising. The physicist and the naturalist parted company long ago, and it only occasionally happens that the methods of the two schools are united, as in the studies of the experimental physiologist, or in the generalizations of the geologist.

The tendency of the day is toward a similar division of interests among naturalists and biologists. The old scientific societies, in which, fifty years ago, all students of science worked side by side, are languishing, and are either replaced by more limited organizations, or are kept together by dividing their membership into " sections,”

The two Agassizs are excellent illustrations of this tendency. Agassiz the elder labored in every field of natural science. He was geologist, palæontologist, botanist, anatomist, physiologist, embryologist, histologist, and bibliographer, an authority upon the geographical distribution of plants and animals, and a specialist in many branches of systematic zoölogy.

His students, though all men of broad sympathies, chose much more limited fields of investigation.

Alexander Agassiz may be taken as a type of this succeeding generation, composed of the men who, since the death of Henry, the Sillimans, the Grays. Baird, and the retirement from active labor of the few of that generation who still survive, are now the seniors in the ranks of science.

The equal of his father, undoubtedly, in mental endowments, thoroughly trained in methods of investigation, and equally enthusiastic as a student of nature, his efforts have taken a very different course.

Although one of the best equipped of living zoölogists, Mr. Agassiz has not studied personally any considerable part, of the material discussed in the book, but has only attempted the study of the sea-urchins, the coral reefs, and the surface fauna of the Gulf Stream.

No less than twenty-four specialists — Americans, English, Scotch, French, German, Swedish, and Russian — have aided in the preparation of these volumes, and the special reports, in which the collections of the Blake are discussed in greater detail ; and to these co-laborers Mr. Agassiz makes full acknowledgment in the preface and in the course of the work.

Many of the specialists whose aid has been thus invoked are the same who participated in the preparation of the magnificent volumes of the final reports of the exploration of the British corvette Challenger. American zoölogists, notably Lyman and Agassiz, have been prominent members of the Challenger staff, a most interesting instance of the unsectarian and catholic spirit of modern science.

It is pleasant to note a disposition on the part of representative scientific men in America to write books intended, like this, for readers not professional naturalists, for of late years the popular exposition of scientific work has been left too much to compilers and amateurs. Recent publications of Langley, Holden, Shaler, Powell, Morse, and others indicate a tendency toward the better practice of former years. It is a well-known fact that Mr. Alexander Agassiz, besides supporting the great museum at Cambridge from his private resources, pays for the printing of all its publications. It is to be hoped it will appear that Americans are prepared not only to read, but to pay for, the printing of such books as Three Cruises of the Blake, and that the author will in due time expand some of its too crowded chapters into volumes.

  1. A Contribution to American Thalassography. Three Cruises of the United States Coast and Geodetic Survey Steamer Blake in the Gulf of Mexico, in the Caribbean Sea, and along the Atlantic Coast of the United States, from 1877 to 1880. By ALEXANDER AGASSIZ. In two volumes. Boston and New York : Houghton, Mifflin & Co. 1888.