There is no need to give an abstract of the contents of these fascinating volumes, for everybody is reading them. Most are probably wishing for more personal details, especially of the American life; but the editorial work is so deftly and delicately done, and "the story of an intellectual life marked by rare coherence and unity" is so well arranged to tell itself and make its impression, that we may thankfully accept what has been given us, though the desired "fulness of personal narrative" be wanting.
Twelve years have passed since Agassiz was taken from us. Yet to some of us it seems not very long ago that the already celebrated Swiss naturalist came over, in the bloom of his manly beauty, to charm us with his winning ways, and inspire us with his overflowing enthusiasm, as he entered upon the American half of that career which has been so beneficial to the interests of natural science. There are not many left of those who attended those first Lowell Lectures in the autumn of 1846—perhaps all the more taking for the broken English in which they were delivered—and who shared in the delight with which, in a supplementary lecture, he more fluently addressed his audience in his mother-tongue.
In these earliest lectures he sounded the note of which his last public utterance was the dying cadence. For, as this biography rightly intimates, his scientific life was singularly entire and homogeneous—if not uninfluenced, yet quite unchanged, by the transitions which have marked the period. In a small circle of naturalists, almost the first that was assembled to greet him on his coming to this country, and of which the writer is the sole survivor, when Agassiz was inquired of as to his conception of "species," he sententiously replied: "A species is a thought of the Creator." To this thoroughly theistic conception he joined the scientific deduction which he had already been led to draw, that the animal species of each geological age, or even stratum, were different from those preceding and following, and also unconnected by natural derivation. And his very last published works reiterated his steadfast conviction that "there is no evidence of a direct descent of later from earlier species in the geological succession of animals." Indeed, so far as we know, he would not even admit that such "thoughts of the Creator" as these might have been actualized in the natural course of events. If he had accepted such a view, and if he had himself apprehended and developed in his own way the now well-nigh assured significance of some of his early and pregnant generalizations, the history of the doctrine of development would have been different from what it is, a different spirit and another name would have been prominent in it, and Agassiz would not have passed away while fighting what he felt to be—at least for the present—a losing battle. It is possible that the "whirligig of time" may still "bring in his revenges," but not very probable.
Much to his credit, it may be said that a good share of Agassiz's invincible aversion to evolution may be traced to the spirit in which it was taken up by his early associate, Vogt, and, indeed, by most of the German school then and since, which justly offended both his scientific and his religious sense. Agassiz always "thought nobly of the soul," and could in no way approve either materialistic or agnostic opinions. The idealistic turn of his mind was doubtless confirmed in his student days at Munich, whither he and his friend Braun resorted after one session at Heidelberg, and where both devotedly attended the lectures of Schelling—then in his later glory—and of Oken, whose "Natur-Philosophie" was then in the ascendant. Although fascinated and inspired by Oken's à priori biology(built upon morphological ideas which had not yet been established, but had, in part, been rightly divined) the two young naturalists were not carried away by it, probably because they were such keen and conscientious observers, and were kept in close communion with work-a-day nature. As Agassiz intimates, they had to resist "the temptation to impose one's own ideas upon nature, to explain her mysteries by brilliant theories rather than by patient study of the facts as we find them," and that "overbearing confidence in the abstract conceptions of the human mind as applied to the study of nature; although, indeed," he adds, "the young naturalist of that day who did not share in some degree the intellectual stimulus given to scientific pursuits by physio-philosophy would have missed a part of his training." That training was not lost upon Agassiz. Although the adage in his last published article, "A physical fact is as sacred as a moral principle," was well lived up to, yet ideal prepossessions often had much to do with his marshalling of the facts.
Another professor at Munich, from whom Agassiz learned much, and had nothing to unlearn, was the anatomist and physiologist Döllinger. He published little, but he seems to have been the founder of modern embryological investigation, and to have initiated his two famous pupils, first Von Baer, and then Agassiz, into at least the rudiments of the doctrine of the correspondence between the stages of the development of the individual animal with that of its rank in the scale of being, and the succession in geological time of the forms and types to which the species belongs: a principle very fertile for scientific zoölogy in the hands of both these naturalists, and one of the foundations of that theory of evolution which the former, we believe, partially accepted, and the other wholly rejected.
The botanical professor, the genial Von Martius, should also be mentioned here. He found Agassiz a student, barely of age; he directly made him an author, and an authority, in the subject of his predilection. Dr. Spix, the zoölogical companion of Martius in Brazilian exploration, died in 1826; the fishes of the collection were left untouched. Martius recognized the genius of Agassiz, and offered him, and indeed pressed him, to undertake their elaboration. Agassiz brought out the first part of the quarto volume on the "Fishes of the Brazilian Expedition of Spix and Martius" before he took his degree of doctor of philosophy, and completed it before he proceeded to that of doctor in medicine, in 1830. The work opened his way to fame, but brought no money. Still, as Martius defrayed all the expenses, the net result compared quite favorably with that of later publications. Moreover, out of it possibly issued his own voyage to Brazil in later years, under auspices such as his early patron never dreamed of.
This early work also made him known to Cuvier; so that, when he went to Paris, a year afterward, to continue his medical and scientific studies—the one, as he deemed, from necessity, the other from choice—he was received as a fellow-savant; yet at first with a certain reserve, probably no more than was natural in view of the relative age and position of the two men; but Agassiz, writing to his sister, says: "This extreme but formal politeness chills you instead of putting you at your ease; it lacks cordiality, and, to tell the truth, I would gladly go away if I were not held fast by the wealth of material of which I can avail myself." But only a month later he writes—this time to his uncle—that, while he was anxious lest he "might not be allowed to examine, and still less to describe, the fossil fishes and their skeletons in the Museum, ... knowing that Cuvier intended to write a work on this subject," and might naturally wish to reserve the materials for his own use; and when the young naturalist, as he showed his own sketches and notes to the veteran, was faintly venturing to hope that, on seeing his work so far advanced, he might perhaps be invited to share in a joint publication, Cuvier relieved his anxiety and more than fulfilled his half-formed desires.
"He desired his secretary to bring him a certain portfolio of drawings. He showed me the contents: they were drawings of fossil fishes, and notes which he had taken in the British Museum and elsewhere. After looking it through with me, he said he had seen with satisfaction the manner in which I had treated this subject; that I had, indeed, anticipated him, since he had intended at some future time to do the same thing; but that as I had given it so much attention, and had done my work so well, he had decided to renounce his project, and to place at my disposition all the materials he had collected and all the preliminary notes he had taken."