Agassiz, as we have already said, though only a student, ranked at this time among the scientific men of Munich. A few young men of like spirit gathered round him, forming a small but select circle who met to discuss scientific subjects. This society soon attracted attention; it was called the little Academy; even the professors gladly took part in it; and those of the students who had the good fortune to be members of it remember the lectures read there, as not the least instructive and interesting part of their scientific course.

Martius was then occupied in publishing his great work on the Natural History of Brazil. He confined himself to the part relating to Botany. His companion, Spix, who was to edit the zoological portion, had just died, leaving many portions of his work unfinished. That relating to Ichthyology, in particular, was barely sketched out. An able zoologist was needed to reduce to order the chaos of new species and genera, and to assign to them their true places in the system. Martius cast his eyes upon his young friend Agassiz, to whom he confided the honorable task of elaborating this important part of the work. It appeared in a folio volume in Latin, with numerous plates; making part of the "Travels in Brazil." From the time of its appearance it gained for its author the rank of an eminent naturalist.

Such occupations necessarily resulted in detaching the young naturalist more and more from his medical studies. His parents, who had already often protested against this too exclusive passion of their son for Natural History, now had recourse to an extreme measure; they withdrew the moderate allowance which they had hitherto granted him. This was a terrible blow for the young man, who found himself thus at once deprived of all means of subsistence, and obliged to renounce what was dearer than all to him, his portfolios; for his allowance had not only supplied his daily wants, but had also been applied to paying for the services of a young artist named Dinkel, whom he had remarked among the crowd of draughtsmen who fill the streets of Munich, and who under his guidance became one of the most skilful painters in this depart

ment.

But, like other passions, the love of science is ingenious in surmounting difficulties. Full of confidence in himself, he applied to the bookseller Cotta, a man who united with great skill in business the most enlarged views. To him he showed the materials he had collected for a Natural History of the Fresh

water Fishes of Europe. The beauty of the drawings, the finish of the details, and above all the enthusiasm of the young man, gained the heart of the old bookseller, who advanced him funds to continue and complete his work.

At the same time Agassiz, like a good son, sought to regain the favor of his parents. For this there was but one thing to be done; namely, to return to Medicine. Until now he had divided his time between his medical and his zoological studies; but now, we may infer that he applied himself seriously to his profession, since not long after he presented himself as candidate for the degree of Doctor, and passed his examination with distinction. But the title of Doctor of Medicine was not enough for him. In the same year he applied for the degree of Doctor of Philosophy, which he received after a public disputation which produced a great sensation in the literary community of Munich.

He undertook to show that woman is superior to man. Mens feminæ viri animo superior, was the theme of his disputation. Such a proposition, coming from a young man whose devotion to the fair sex was well known, could not fail to attract attention. It was received with the most various sentiments. The young applauded the irresistible arguments of the youthful candidate; puritanic conservatives, and those belonging to what is called in Germany the Historical School, thundered against these ideas, as revolutionary and calculated to subvert the order of society. The sphere of woman, they thought, should not be extended beyond the kitchen and the laundry.

After this double examination, Agassiz received permission from his parents to visit Vienna. The object of this journey was the completion of his medical studies; but on his arrival he devoted himself again to his favorite pursuit, and was oftener to be met with at the Museum than in the hospital. Here he made the acquaintance of many distinguished naturalists, among others of Fitzinger; and applied himself to the special study of Ichthyology.

This study, with him, was not confined to living species. He had extended his researches to the fossil kinds, and the débris (often admirably preserved,) found in the fresh-water deposits of Oeningen, in Switzerland, had attracted his particular attention. He found that most of the species said to be identical with those of the present epoch, were different, and therefore had drawings made of a great number; so that when

be returned to Switzerland his portfolio contained almost as many fossil as recent species. What was he to do with all these materials? His parents having already made great sacrifices for him, and seeing no guarantee for the future, were impatient for him to begin his medical career. In this conflict of his tastes and his filial duties, his position was difficult.

But he had not yet seen Paris, and he could not make up his mind to commence practice without having examined the rich collections of that great capital; without having visited the Jardin des Plantes; and above all, without having heard Cuvier, whose renown filled the world.

But how was he to find means to go to Paris? His parents were neither able nor willing to contribute any thing towards it. Fortunately a neighbouring clergyman, a friend of his father, who had always entertained the highest opinion of his talents, having just inherited a small sum of money, thought he could not employ it better than in aiding the project of his young friend.

On his arrival in Paris, Agassiz lost no time in seeking out the two most eminent men of the age, then residing in that city-Cuvier and Humboldt.

Cuvier, in order to assuage his grief for the death of his daughter, had just commenced his great work on Fishes, and received with eagerness every thing concerning fossil species. Agassiz relied upon his portfolio for his introduction to the great naturalist. Cuvier was so much astonished by it, that after a second interview he informed Agassiz that he would give up the projected publication and make over to him all his materials, if he would undertake to describe them. For those who know the value which the materials for a literary work acquire in the eyes of an author, this incident by itself will be sufficient proof that Cuvier's moral character was equal to his intellectual power. From this moment Agassiz continued on intimate terms with Cuvier's family, until the death of that great man, and we have heard him say that the happiest moments of his life were passed in Cuvier's cabinet.

After the death of Cuvier (1832), Agassiz returned to Switzerland, hoping to obtain a professorship in some of the public establishments of the Canton de Vaud. Being disap pointed in this, he accepted the invitation of some citizens of Neufchatel to establish himself in that city, where they were preparing to reorganize the college. He was soon after appointed Professor of Natural History, a place which he filled until his departure for the United States.

Alexander von Humboldt,—who has enjoyed the rare privilege of being able to assist so many men of talent, was from the first the devoted friend of Agassiz, and it was his patronage that enabled our naturalist to commence in 1833, so soon after his arrival in Switzerland, the publication of his great work on Fossil Fishes; which he dedicated to Humboldt, and of which we intend to say a few words, as of all his works this made the greatest sensation, and it is this that obtained for him the eminent rank which he now holds in the scientific world.

This work consists of five volumes, with an atlas of about four hundred folio plates, and comprises descriptions and fig ures of nearly a thousand species of fossil fishes. All the specimens are represented of the natural size, with the colors of the bed from which they were taken. It was impossible that so many new species should be made known without rendering many alterations necessary in the science of Ichthyology; new types were established, and the affinities of various groups and families to each other more clearly shown. Moreover, Agassiz did not confine himself to establishing a vast number of species, genera, and even families. Beside this he founded an entirely new classification, based principally on the importance of the fossil fishes.

Cuvier makes two general divisions among Fishes; the Osseous and the Cartilaginous fishes. Agassiz also separates the Osseous fishes from the Cartilaginous, of which he makes his first order, that of the Placoïdians; but he divides the Osseous fishes again into three other equally important orders; so that the class of Fishes is divided into four orders; namely, 1. The Placoïdians; 2. The Ganoïdians; 3. The Ctenoïdians; and 4. The Cycloïdians. This classification is not founded on the skeleton, like that of Cuvier, but on the nature of the outward integuments, the scales. Agassiz starts with the principle that the outward covering of fishes is the reflex of their internal organization. With this principle he examines the different families of the class of Fishes, with respect to their scales, and finds in the conformation of the external integument a variety of characters, on which he founds his classification. As to this, it is to be remarked at the outset, that all the Osseous fishes, with the exception of a few genera, are furnished with horny scales; while the skin of the Cartilaginous fishes is covered with plates or spines, of a peculiar form, known under the names of shagreen, &c. The scales of the

Osseous fishes are constructed on a totally different plan, and the differences are so marked, that Mr. Agassiz considered them a sufficient foundation for his three orders of Cycloïdians, Ctenoïdians and Ganoïdians. The two former, which comprise almost all the Osseous fishes of the present epoch, both have horny scales; but they differ in this, that the Ctenoïdians have the posterior edge of the scales indented, while in the Cycloïdians this border is entire. He seeks to prove that this distinction, apparently insignificant, is, in truth, founded in nature, being the expression of a fundamental character which reveals itself equally in other parts of the body. Thus, fishes having indented or pectinated scales, have generally prickles on the head, the opercula, and various parts of their body; while the others-the Cycloïdians—are smooth, and without defence. Mr. Agassiz considers the Perch, with the analogous species, as the type of his order of Ctenoïdians; and the family of the Carp, Salmon, Pike, &c., as typical of the Cycloïdians. This division corresponds,

therefore, to a certain extent, with Cuvier's division of fishes into Acanthopterygians and Malacopterygians.

The second order, that of the Ganoïdians, seems to have a yet more satisfactory foundation. There have been found in the Nile and in the rivers of North America, two fishes which have always puzzled the ichthyologists; that of the Nile is known under the name of Bichir (Polypterus Bichir); the other, which is found in America, is called the Gar-pike (Lepi dosteus), having some resemblance to the Pike. Both these fishes are furnished with scales of very peculiar form and structure. Instead of being arranged in the manner of rooftiles, -as in most fishes,-they are placed simply side by side, the surface being covered with a coat of enamel, making a very solid cuirass. On examining these fishes in an anatomical point of view, Mr. Agassiz found that the skeleton presented no less striking differences than the scales and the soft parts of the body. Nevertheless, it seemed hazardous to separate them altogether from the other great families; and particularly when the smallness of their number was considered, it seemed contrary to all method to place them in the same rank with the Placoïdians on one side, and the Osseous fishes on the other. But the procedure, though not authorized by the study of the living fishes, was justified by an examination of fossil species. Here is displayed a whole ichthyological fauna, having the characters neither of the Osseous