On a loose sheet come the "nuts to pick." It contains a long list of mooted questions, a few of which are given here to show the exchange of thought between Aga.s.siz and his friend, the one propounding zoological, the other botanical, puzzles. Although most of the problems were solved long ago, it is not uninteresting to follow these young minds in their search after the laws of structure and growth, dimly perceived at first, but becoming gradually clearer as they go on. The very first questions hint at the law of Phyllotaxis, then wholly unknown, though now it makes a part of the most elementary instruction in botany.* (* Botany owes to Alexander Braun and Karl Schimper the discovery of this law, by which leaves, however crowded, are so arranged around the stem as to divide the s.p.a.ce with mathematical precision, thus giving to each leaf its fair share of room for growth.)

"1. Where is the first diverging point of the stems and roots in plants, that is to say, the first geniculum?

"2. How do you explain the origin of those leaves on the stem which, not arising from distinct geniculi, are placed spirally or scattered around the stem?

"3. Why do some plants, especially trees (contrary to the ordinary course of development in plants), blossom before they have put forth leaves? (Elm-trees, willow-trees, and fruit-trees.)

"4. In what succession does the development of the organs of the flower take place?--and their formation in the bud? (Compare Campanula, Papaver.)

"5. What are the leaves of the Spergula?

"6. What are the tufted leaves of various pine-trees? (Pinus sylvestris, Strobus, Larix, etc.). . .

"8. What is individuality in plants?"

The next letter contains Aga.s.siz's answer to Dr. Leuckart's questions concerning the eggs he had sent him, and some farther account of his own observations upon them.

AGa.s.sIZ TO BRAUN.

NEUCHATEL, June 20, 1827.

. . .Now you shall hear what I know of the "Hebammen Krote." How the fecundation takes place I know not, but it must needs be the same as in other kinds of the related Bombinator; igneus throws out almost as many eggs hanging together in cl.u.s.ters as obstetricans; fuscus throws them out from itself in strings (see Roseld's ill.u.s.tration). . .I have now carefully examined the egg cl.u.s.ters of obstetricans; all the eggs are in one string and hang together.

This string is a bag, in which the eggs lie inclosed at different distances, though they seem in the empty s.p.a.ce to be fallen, thread-like, together. But if you stretch the thread and press the eggs, they change their places, and you can distinctly see that they lie free in the bag, having their own membranous envelopes corresponding to those of other batrachian eggs. Surely this species seeks the water at the time of fecundation, for so do all batrachians, the water being indeed a more fitting medium for fecundation than the air. . .It is certain that the eggs were already fecundated when we found them in the ground, for later, I found several not so far advanced as those you have, and yet after three weeks I had tadpoles from them. In those eggs which were in the lowest stage of development (how they may be earlier, nescio), nothing was clearly visible; they were simply little yellow b.a.l.l.s.

After some days, two small dark spots were to be seen marking the position of the eyes, and a longitudinal streak indicated the dorsal ridge. Presently everything became more distinct; the mouth and the nasal opening, the eyes and the tail, which lay in a half circle around the body; the skin was so transparent that the beating of the heart and the blood in the vessels could be easily distinguished; the yolk and the yolk sac were meanwhile sensibly diminished. The movements of the little animal were now quite perceptible,--they were quick and by starts. After three or four weeks the eggs were as large as peas; the bags had burst at the spots where the eggs were attached, and the little creatures filled the egg envelopes completely. They moved incessantly and very quickly. Now the female stripped off the eggs from her legs; she seemed very uneasy, and sprang about constantly in the tank, but grew more quiet when I threw in more water. The eggs were soon free, and I laid them in a shallow vessel filled with fresh water.

The restlessness among them now became greater, and behold! like lightning, a little tadpole slipped out of its egg, paused astonished, gazed on the greatness of the world, made some philanthropic observations, and swam quickly away. I gave them fresh water often, and tender green plants as well as bread to eat.

They ate eagerly. Up to this time their different stages of development had been carefully drawn by my sister. I now went to Vallorbe; they promised at home to take care of my young brood, but when I returned the tadpoles had been forgotten, and I found them all dead; not yet decayed, however, and I could therefore preserve them in alcohol. The gills I have never seen, but I will watch to see whether they are turned inward. . .

BRAUN TO AGa.s.sIZ.

CARLSRUHE, August 9, 1827.

. . .This is to tell you that I have determined to leave Heidelberg in the autumn and set forth on a pilgrimage to Munich, and that I invite you to be my traveling companion. Judging by a circ.u.mstantial letter from Dollinger, the instruction in the natural sciences leaves nothing to be desired there. Add to this that the lectures are free, and the theatre open to students at twenty-four kreutzers. No lack of advantages and attractions, lodgings hardly more expensive than at Heidelberg, board equally cheap, beer plenty and good. Let all this persuade you. We shall hear Gruithuisen in popular astronomy, Schubert in general natural history, Martius in botany, Fuchs in mineralogy, Seiber in mathematics, Starke in physics, Oken in everything (he lectures in winter on the philosophy of nature, natural history, and physiology). The clinical instruction will be good. We shall soon be friends with all the professors. The library contains whatever is best in botany and zoology, and the collections open to the public are very rich. It is not known whether Sch.e.l.ling will lecture, but at all events certain of the courses will be of great advantage. Then little vacation trips to the Salzburg and Carinthian Alps are easily made from there! Write soon whether you will go and drink Bavarian beer and Schnapski with me, and write also when we are to see you in Heidelberg and Carlsruhe. Remind me then to tell you about the theory of the root and poles in plants.

As soon as I have your answer we will bespeak our lodgings from Dollinger, who will attend to that for us. Shall we again house together in one room, or shall we have separate cells in one comb, namely, under the same roof? The latter has its advantages for gra.s.s-gatherers and stone-cutters like ourselves. . .Hammer away industriously at all sorts of rocks. I have collected at Auerbach, Weinheim, Wiesloch, etc. But before all else, observe carefully and often the wonderful structure of plants, those lovely children of the earth and sky. Ponder them with child-like mind, for children marvel at the phenomena of nature, while grown people often think themselves too wise to wonder, and yet they know little more than the children. But the thoughtful student recognizes the truth of the child's feeling, and with his knowledge of nature his wonder does but grow more and more. . .

CHAPTER 2.

1827-1828: AGE 20-21.

Arrival in Munich.

Lectures.

Relations with the Professors.

Sch.e.l.ling, Martius, Oken, Dollinger.

Relations with Fellow-Students.

The Little Academy.

Plans for Traveling.

Advice from his Parents.

Vacation Journey.

Tri-Centennial Durer Festival at Nuremberg.

Agssiz accepted with delight his friend's proposition, and toward the end of October, 1827, he and Braun left Carlsruhe together for the University of Munich. His first letter to his brother is given in full, for though it contains crudities at which the writer himself would have smiled in after life, it is interesting as showing what was the knowledge possessed in those days by a clever, well-informed student of natural history.

TO HIS BROTHER AUGUSTE.

MUNICH, November 5, 1827.

. . .At last I am in Munich. I have so much to tell you that I hardly know where to begin. To be sure that I forget nothing, however, I will give things in their regular sequence. First, then, the story of my journey; after that, I will tell you what I am doing here. As papa has, of course, shown you my last letter, I will continue where I left off. . .

From Carlsruhe we traveled post to Stuttgart, where we pa.s.sed the greater part of the day in the Museum, in which I saw many things quite new to me; a llama, for instance, almost as large as an a.s.s.

You know that this animal, which is of the genus Camelus, lives in South America, where it is to the natives what the camel is to the Arab; that is to say, it provides them with milk, wool, and meat, and is used by them, moreover, for driving and riding. There was a North American buffalo of immense size; also an elephant from Africa, and one from Asia; beside these, a prodigious number of gazelles, deer, cats, and dogs; skeletons of a hippopotamus and an elephant; and lastly the fossil bones of a mammoth. You know that the mammoth is no longer found living, and that the remains. .h.i.therto discovered lead to the belief that it was a species of carnivorous elephant. It is a singular fact that some fishermen, digging recently on the borders of the Obi, in Siberia, found one of these animals frozen in a ma.s.s of ice, at a depth of sixty feet, so well preserved that it was still covered with hair, as in life.

They melted the ice to remove the animal, but the skeleton alone remained complete; the hide was spoiled by contact with the air, and only a few pieces have been kept, one of which is in the Museum at Stuttgart. The hairs upon it are as coa.r.s.e as fine twine, and nearly a foot long. The entire skeleton is at St. Petersburg in the Museum, and is larger than the largest elephant. One may judge by that what havoc such an animal must have made, if it was, as its teeth show it to have been, carnivorous. But what I would like to know is how this animal could wander so far north, and then in what manner it died, to be frozen thus, and remain intact, without decomposing, perhaps for countless ages. For it must have belonged to a former creation, since it is nowhere to be found living, and we have no instance of the disappearance of any kind of animal within the historic period. There were, besides, many other kinds of fossil animals. The collection of birds is very beautiful, but it is a pity that many of them are wrongly named. I corrected a number myself. . .From Stuttgart we went to Esslingen, where we were to visit two famous botanists. One was Herr Steudel; a sombre face, with long overhanging black hair, almost hiding the eyes,--a very Jewish face. He knows every book on botany that appears, has read them all, but cares little to see the plants themselves; in short, he is a true closet student. He has a large herbarium, composed in great part of plants purchased or received as gifts.

The other, Professor Hochstetter, is an odd little man, stepping briskly about in his high boots, and having always a half suppressed smile on his hips whenever he takes the pipe from between his teeth. A very good man, however, and extremely obliging; he offered us every civility. As we desired not only to make their acquaintance, but to win from these botanists at least a few gra.s.ses, we presented ourselves like true commis voyageurs, with dried herbs to sell, each of us having a package of plants under his arm,--mine being Swiss, gathered last summer, Braun's from the Palatinate. We gave specimens to each, and received in exchange from Steudel some American plants; from Hochstetter some from Bohemia, and others from Moravia, his native country. From Esslingen we were driven to Goeppingen, in the most frightful weather possible; it rained, snowed, froze, blew, all at once. It was a pity, since our road lay through one of the prettiest valleys I have ever seen, watered by the Neckar, and bordered on both sides by mountains of singular form and of considerable height. They are what the Wurtembergers call the Suabian Alps, but I think that Chaumont is higher than the loftiest peak of their Alps. Here we found an old Heidelberg acquaintance, whose father owns a superb collection of fossils, especially of sh.e.l.ls and zoophytes. He has also quite a large collection of sh.e.l.ls from the Adriatic Sea, but among these last not one was named. As we knew them, we made it our duty to arrange them, and in three hours his whole collection was labeled. Since he has duplicates of almost everything, he promised, as soon as he should have time, to make a selection from these and send them to us. Could we have stayed longer we might have picked out what we pleased, for he placed his collection at our disposal.

But we were in haste to arrive here, so we begged him to send us, at his leisure, whatever he could give us.

Thence we continued our journey by post, because it still rained, and the roads were so detestable that with the best will in the world we could not have made our way on foot. In the evening we reached Ulm, where, owing to the late hour, we saw almost nothing except the famous belfry of the cathedral, which was distinctly visible as we entered the city. After supper we continued our journey, still by post, wishing to be in Munich the next day. I have never seen anything more beautiful than the view as we left Ulm. The moon had risen and shone upon the belfry like broad daylight. On all sides extended a wide plain, unbroken by a single inequality, so far as the eye could distinguish, and cut by the Danube, glittering in the moonbeams. We crossed the plain during the night, and reached Augsburg at dawn. It is a beautiful city, but we merely stopped there for breakfast, and saw the streets only as we pa.s.sed through them. On leaving Augsburg, the Tyrolean Alps, though nearly forty leagues away, were in sight. About eighteen leagues off was also discernible an immense forest; of this we had a nearer view as we advanced, for it encircles Munich at some distance from the town. We arrived here on Sunday, the 4th, in the afternoon. . .My address is opposite the Sendlinger Thor Number 37.

I have a very pretty chamber on the lower floor with an alcove for my bed. The house is situated outside the town, on a promenade, which makes it very pleasant. Moreover, by walking less than a hundred yards, I reach the Hospital and the Anatomical School, a great convenience for me when the winter weather begins. One thing gives me great pleasure: from one of my windows the whole chain of the Tyrolean Alps is visible as far as Appenzell; and as the country is flat to their very base, I see them better than we see our Alps from the plain. It is a great pleasure to have at least a part of our Swiss mountains always in sight. To enjoy it the more, I have placed my table opposite the window, so that every time I lift my head my eyes rest on our dear country. This does not prevent me from feeling dull sometimes, especially when I am alone, but I hope this will pa.s.s off when my occupations become more regular. . .

A far more stimulating intellectual life than that of Heidelberg awaited our students at Munich. Among their professors were some of the most original men of the day,--men whose influence was felt all over Europe. Dollinger lectured on comparative anatomy and kindred subjects; Martius and Zuccarini on botany. Martius gave, besides, his so-called "Reise-Colleg," in which he instructed the students how to observe while on their travels. Sch.e.l.ling taught philosophy, the t.i.tles of his courses in the first term being, "Introduction to Philosophy" and "The Ages of the World"; in the second, "The Philosophy of Mythology" and "The Philosophy of Revelation."

Sch.e.l.ling made a strong impression upon the friends. His manner was as persuasive as his style was clear, and his mode of developing his subject led his hearers along with a subtle power which did not permit fatigue. Oken lectured on general natural history, physiology, and zoology, including his famous views on the philosophy of nature (Natur-philosophie). His lectures gave occasion for much scientific discussion, the more so as he brought very startling hypotheses into his physiology, and drew from them conclusions which even upon his own showing were not always in accordance with experience. "On philosophical grounds," he was wont to say, when facts and theory thus confronted each other, "we must so accept it." Oken was extremely friendly with the students, and Aga.s.siz, Braun, and Schimper (who joined them at Munich) pa.s.sed an evening once a week at his house, where they listened to scientific papers or discussed scientific matters, over a pipe and a gla.s.s of beer. They also met once a week to drink tea at the house of Professor von Martius, where, in like manner, the conversation turned upon scientific subjects, unless something interesting in general events gave it a different turn. Still more beloved was Dollinger, whose character they greatly esteemed and admired while they delighted in his instruction. Not only did they go to him daily, but he also came often to see them, bringing botanical specimens to Braun, or looking in upon Aga.s.siz's breeding experiments, in which he took the liveliest interest, being always ready with advice or practical aid. The fact that Aga.s.siz and Braun had their room in his house made intercourse with him especially easy. This room became the rendezvous of all the aspiring, active spirits among the young naturalists at Munich, and was known by the name of "The Little Academy." Schimper, no less than the other two, contributed to the vivid, enthusiastic intellectual life, which characterized their meetings. Not so happy as Aga.s.siz and Braun in his later experience, the promise of his youth was equally brilliant; and those who knew him in those early days remember his charm of mind and manner with delight. The friends gave lectures in turn on various subjects, especially on modes of development in plants and animals. These lectures were attended not only by students, but often by the professors.

Among Aga.s.siz's intimate friends in Munich, beside those already mentioned, was Michah.e.l.les, the distinguished young zoologist and physician, whose early death in Greece, where he went to practice medicine, was so much regretted. Like Aga.s.siz, he was wont to turn his room into a menagerie, where he kept turtles and other animals, brought home, for the most part, from his journeys in Italy and elsewhere. Mahir, whose name occurs often in the letters of this period, was another college friend and fellow-student, though seemingly Aga.s.siz's senior in standing, if not in years, for he gave him private instruction in mathematics, and also a.s.sisted him in his medical studies.

TO HIS SISTER CECILE,

MUNICH, November 20, 1827.

. . .I will tell you in detail how my time is spent, so that when you think of me you may know where I am and what I am doing. In the morning from seven to nine I am at the Hospital. From nine to eleven I go to the Library, where I usually work at that time instead of going home. From eleven till one o'clock I have lectures, after which I dine, sometimes at one place, sometimes at another, for here every one, that is, every foreigner, takes his meals in the cafes, paying for the dinner on the spot, so that he is not obliged to go always to the same place. In the afternoon I have other lectures on various subjects, according to the days, from two or three till five o'clock. These ended, I take a walk although it is then dark. The environs of Munich are covered with snow, and the people have been going about in sleighs these three weeks. When I am frozen through I come home, and set to work to review my lectures of the day, or I write and read till eight or nine o'clock. Then I go to my cafe for supper. After supper I am glad to return to the house and go to bed.

This is the course of my daily life, with the single exception that sometimes Braun and I pa.s.s an evening with some professor, discussing with all our might and main subjects of which we often know nothing; this does not, however, lessen the animation of the talk. More often, these gentlemen tell us of their travels, etc. I enjoy especially our visits to M. Martius, because he talks to us of his journey to Brazil, from which he returned some years ago, bringing magnificent collections, which he shows us whenever we call upon him. Friday is market day here, and I never miss going to see the fishes to increase my collection. I have already obtained several not to be found in Switzerland; and even in my short stay here I have had the good fortune to discover a new species, of which I have made a very exact description, to be printed in some journal of natural history. Were my dear Cecile here, I should have begged her to draw it nicely for me. That would have been pleasant indeed. Now I must ask a stranger to do it, and it will have by no means the same value in my eyes. . .

TO HIS BROTHER AUGUSTE.

MUNICH, December 26, 1827.

. . .After my long fast from news of you, your letter made me very happy. I was dull besides, and needed something to cheer me. . .

Since my talk about natural history does not bore you, I want to tell you various other things about it, and also to ask you to do me a favor. I have stuffed a superb otter lately; next week I shall receive a beaver, and I have exchanged all my little toads from Neuchatel for reptiles from Brazil and Java. One of our professors here, who is publishing a natural history of reptiles, will introduce in his work my description of that species, and my observations upon it. He has already had lithographed those drawings of eggs that Cecile made for me, as well as the colored drawings made for me by Braun's sister when I was at Carlsruhe. My collection of fishes is also much increased, but I have no duplicates left of the species I brought with me. I have exchanged them all. I should therefore be greatly obliged if you would get me some more of the same. I will tell you what kinds I want, and how you are to forward them. I have still at Cudrefin several jars of thick green gla.s.s. When you go there take them away with you, fill them with alcohol, and put into them as many of these fishes as you can find for me. Put something between every two specimens, to prevent them from rubbing against each other; pack them in a little box wrapped in hay, and send them either by a good opportunity or in the least expensive way. The kinds I want are [here follows the list]. . .It will interest you to know that I am working with a young Dr. Born upon an anatomy and natural history of the fresh-water fishes of Europe. We have already gathered a great deal of material, and I think by the spring, or in the course of the summer, we shall be able to publish the first number. This will bring in a little ready money for a short journey in the vacation.

I earnestly advise you to while away your leisure hours with study.

Read much, but only good and useful books. I promised to send you something; do not think, because I have not done so yet, that I have forgotten it. On the contrary, the difficulty of choosing is the cause of the delay; but I will make farther inquiry as to what will suit you best and you shall have my list. Meantime remember to read Say, and if you have not already begun it, do not put it off.

Remember that statistical and political knowledge alone distinguishes the true merchant from the mere tradesman, and guides him in his undertakings. . .A merchant familiar with the products of a country, its resources, its commercial and political relations with other countries, is much less likely to enter into speculations based on false ideas, and therefore of doubtful issue.

Write me about what you are reading and about your plans and projects, for I can hardly believe that any one could exist without forming them: I, at least, could not.

The last line of this letter betrays the restless spirit of adventure growing out of the desire for larger fields of activity and research. Tranquilized for a while in the new and more satisfying intellectual life of Munich, it stirred afresh from time to time, not without arousing anxiety in friends at home, as we shall see. The letter to which the following is an answer has not been found.

FROM HIS MOTHER.

ORBE, January 8, 1828.

. . .Your letter reached me at Cudrefin, where I have been pa.s.sing ten days. With what pleasure I received it,--and yet I read it with a certain sadness too, for there was something of ennui, I might say of discontent, in the tone. . .Believe me, my dear Louis, your att.i.tude is a wrong one; you see everything in shadow. Consider that you are exactly in the position you have chosen for yourself; we have in no way opposed your plans. We have, on the contrary, entered into them with readiness, saying amen to your proposals, only insisting upon a profession that would make us easy about your future, persuaded as we are that you have too much energy and uprightness not to wish to fill honorably your place in society.