VI. LIFE, OR MECHANISM-WHICH?1 "Tu cuncta superno Ducis ab exemplo, pulchrum pulcherimus ipse BOETHIUS, De Consol., 9. "What time this world's great workmaister did cast That wondrous patterne, wheresoe'er it be, ONE day the poet Goethe, when in his advanced age, was riding home to Weimar with his friend Eckermann, and conversing on the immortality of the soul. They turned by Tiefurt into the Weimar road, and stopped at a spot, where, like other travellers, I have often meditated on Goethe's career; and they had from that outlook a majestic view of the setting sun. The great poet and philosopher remained for many minutes in perfect silence, and at last said with mystic but tremorless emphasis, Untergehend sogar ist's immer dieselbige Sonne. Setting, nevertheless the sun is always the same sun. I am fully convinced that our spirit is a being of a nature quite indestructible, and that its activity continues from eternity to eternity." This man knew all philosophies and all art-materialism, realism, pantheism, the wildest scepticism, and, I fear, not a little of the most infamous sensualism; but his was at least a free mind and a modern one. Here, however, was his conclusion concerning the possibility of the existence of the soul in separation from the body: Setting, nevertheless the soul is always the same soul. Will you enter to-day, my friends, into Goethe's brain at that instant, and remain 2 1 The fifty-first lecture in the Boston Monday Lectureship, delivered in the Park Street Church. Goethe, Conversations with Eckermann, Trans. by J. Oxenford, Bohn's ed., p. 84. there during this discussion, lynx-eyed, I care not how thoroughly so, but earnest? It is incontrovertible that we, too, a little while ago, were not in the world, and that we, too, a little while hence, shall be here no longer. The sun hastes to the west as fast at noon as in the last moment before sunset. New lands in our age can be discovered only in old lands. Schliemann, on the Plain of Troy, has shown us a city of great antiquity; and he has done so by studying an old land beneath its soil. We are reaching the bottom of the Roman forum; we understand, as never before, the environment of the Acropolis, because we are looking with the spade for new lands in the old lands. If a new continent has been discovered anywhere in the last twenty-five years, it has been in the ancient continent of living tissues. We are to enter on that strange country; we draw near to it across turbulent seas; and I think, that, as the Santa Maria ploughs tossing across the waves toward the west, we already begin to see carved wood occasionally, symbol of life behind the watery horizon. Already, as we approach this new continent, do we not find now and then a poor floating spray of red berries? Are these little birds not of a kind always cradled on the land? Are not the shapes of the very clouds, as the sun goes down, some indication that we shall at last reach the firm, happy shore? Is there not breathed upon us out of the undescried but nearing coast an odour as of spices and balm, and frankincense and myrrh, and dates and palms-a fragrant atmosphere that comes in the twilight wind off the continent of an unseen Holy? We have not landed on the new coast yet; but they who walk late on the deck of the Santa Maria have seen a light rise and fall ahead of us. We are to look to-day at the thickening signs of the approach of a whole new continent in philosophy that lies hardly out of sight. It will be a land assuredly of firm hope of immortality, and therefore a land of inspiration such as no spiced breath of the tropics ever breathed into the physical nostrils. Our souls are sick from lack of the more heavily fragrant airs out of the blessed isles of certainties as to what is behind the veil. It is already certain that we are to discover a new land, and that the inhabitant of it is life, not mechanism. Two positions of much importance have been proved, I hope, in lectures preceding this: first, the explicit and entire agreement of Beale and Huxley as to all the central facts concerning living tissues, and this in spite of the disagreement of these authorities on other points; and, secondly, the crescent unanimity of experts for thirtyfive years as to those same facts. The two initial propositions which I think I have established are, that rival experts agree, and that they have agreed for more than a quarter of a century, on the facts fundamental in our discussions here. Let us, now, summarise our knowledge of bioplasm, remembering, as we do so, that we have the authority of Huxley, of Carpenter, of Frey, of Dalton, of Beale, of Drysdale, of Bain, of Ranke, and of Lölliker. You will permit me, for the sake of clearness of thought, to number the points of our positive knowledge in biological science. Bioplasm, otherwise called protoplasm, or germinal matter, 1. Is transparent; 2. Colourless; 3. Viscid, or glue-like; 4. Under the highest microscopical powers is apparently structureless; 5. Exhibits these characters at every period of its existence; 6. Shows itself, under all the tests known to physical science, to be the same in the animal and in the plant, in the sponge and in the brain ; 7. Is capable of throbbing movements, or of advancing one portion of itself beyond another portion ; 8. Is capable of rectilinear movements; 9. Executes so many movements, that the same mass probably never twice in its life assumes the same form; 10. May exist in masses less than one one-hundred-thousandth of an inch, or as large as one two-hundredth of an inch in diameter, but, as constituting the nuclei of fully-formed cells, is usually found in masses from one six-thousandth to one three-thousandth of an inch in diameter; 11. Absorbs nutrient matter, which may be either inorganic or formed material; 12. Instantaneously changes this dead matter into living matter; 13. Does so by a process which no human science can imitate or explain; 14. Throws off formed material to constitute a cell-wall; 15. Develops within itself a nucleus, and within that a nucleolus ; 16. May exist and move, however, without cell-wall or nucleus ; 17. Spins the threads of nerves, arteries, veins, bones, and all the mechanism of the system, by throwing off formed material; 18. Weaves these threads into the infinity of co-ordinated designs in the plant and animal ; 19. Can by no possible outer environment be made to produce nerve if it should produce muscle, or muscle if it should produce nerve, and so of every other tissue, secretion, and deposit; 20. Is so thickly scattered through the tissues, that there is scarcely a space one-five-hundredth of an inch in size without its portion of it; 21. Is capable of self-subdivision; 22. In its self-subdivided parts has all its original powers; 23. Always arises from preceding bioplasm; 24. Constitutes about one-fifth of the bulk of living bodies; 25. Is the sole agency by which every kind of living thing is made, or, so far as known, has been made or ever will be made; 26. When it divides itself, is preceded sometimes in that act by the division of its nucleus, and sometimes not; 27. May throw off a portion of itself without a nucleus, and develop a nucleus in the detached portion. 28. Forms nuclei and nucleoli, which appear to differ sexually, as it is only after the intermingling of these in certain cases that multiplication takes place ; 29. Does not transform the nucleus, or nucleolus, directly into formed material; 30. Transforms it into ordinary bioplasm, and thus into formed material; 31. When recently dead, will take a carmine stain from the solution of carmine in ammonia, as formed material will not; 32. At its death is resolved into fibrine, albumen, fatty matter, and salts; 33. Forms thus the spontaneously coagulable substance on the diffusion of which through the body the rigidity of the frame after death depends; 34. Is in direct continuity with formed material while the latter is in process of formation. Such is the most interesting, by far, of all the objects known to physical science. Carmine staining, the great discovery of 1856 and 1860, must take place immediately after the death of the bioplasm, or it cannot be successfully executed. Many unskilful manipulators in the laboratory, and amateurs without number, have endeavoured to stain the tissue of plants and animals, and have waited too long after its death, and have failed. Sometimes, too, they have not rightly compounded the materials for their carmine solution, a distinct receipt for which you will find in Beale's work on the microscope. When the process of staining is performed soon after the death of a tissue, all germinal points or bioplasts in it come out with a red colour; but the formed material is not stained at all. [From this point on, Mr. Cook referred to large coloured diagrams hung on the wall back of the platform.] These eloquent representations of stained tissues are exact reproductions of Dr. Beale's famous illustrations, and were made by Mr. Stone, an artist of the Studio building, who spoke admiringly of Beale's illustrations the instant he saw them. Here is the whole cell with its wall, bioplast, and nucleus (see plate I. fig. 1). Two currents exist in every cell,-one flowing inward in the direction of this arrow, and the other passing out from the centre of the bioplast in the direction of this arrow. Every particle of matter that can be found in a living being is of one of three kinds,-nutrient matter, living matter, or formed matter. Nutrient matter comes through the wall of the cell, and, entering into the bioplasm, is there transformed into living matter. You had better not take a cell, however, as the type of the elementary part in the living tissue. If you are to be abreast of the very latest investigations concerning the cell-theory, you will take a naked mass of bioplasm like this as the elementary part (see plate I. fig. 2). As I showed you in my last lecture on both Huxley's and Beale's authority, it is not essential at all that there be a wall of formed material around the naked mass of bioplasm. It is not essential at all that there be a nucleus within it. That is the advance we have made since 1838. Nevertheless, if you are to understand the action of these currents, it is well to keep in mind the cell-wall. Nutrient material may pass through the cell-wall in animal tissues just as sap passes through the intercellular substance in vegetable tissues. When once in the bioplast, the nutrient matter is seized on by this living matter, which you see coloured with carmine in all these illustrations, and nuclei are developed in the bioplast, and nucleoli within the nuclei. The bioplast produces the nucleus, and not the nucleus the bioplast. It throws off formed material around its quivering edges, and thus forms a cell-wall. In that wall the oldest formed material is on the outside, and the next oldest just within, and so on to the inner part of the wall, which is in physical continuity with the bioplasm. Movement is going on all the while in any naked mass of bioplasm. Here is a bioplast, naked, colourless, structureless matter; and it moves so that it takes these many shapes in five seconds, and these many other shapes in one minute (see plate I. figs. 2 and 3). Here we must hold fast to the Ariadne clew, that every change must have an adequate cause. We come here to fathomless design; but let us enter by slow stages on these sublimities of research. Here is a young tendon, and here is an old tendon. The living matter is red, as you notice, and runs in lines through the tendon; and yet the tendon is narrow. But in the old tendon the formed material is more abundant than in the new; and yet all the formed material which makes an increased thickness in the old has been thrown off by these bioplasts. They have here thrown off formed material so as to make a tendon, which is, as you know, a structure very different from muscular fibre and from nervous fibre. Here is one set of bioplasts that is intended to weave a tendon, here one that is to weave a muscular fibre, and here one that is to weave a nervous fibre. There is no possible external influence that can make them exchange offices with each other. You have here a tendon, there a muscle, there a nerve, all woven by these bioplasts. We know that they are thus woven, and that every change must have an adequate cause. Adhere, gentlemen, to that axiomatic truth, though the heavens fall. From your bioplast spindles flows off formed matter-here a miracle of muscle, there a miracle of tendon, there a miracle of nerve. The cellular integument is not unworthy of notice; for that shows us the career of its bioplasts from the first to the last. You have here the skin that covers one of the papilla on the tongue of a frog (see plate II. fig. 1). That infinitely delicate membrane that covers the little sensitive points on the tongue is here magnified. You notice that the bioplasts on the lower or inner side are young, and that there is not much formed material around them. There are no distinct cells in the younger part of a tissue. This intercellular substance is not formed into the ring-shapes which you see further on, where the tissue is older. As the bioplasts grow, the formed material about them increases in thickness, until it becomes so thick that the nutrient matter will not go through the cell-walls. Then the bioplasts languish; they grow smaller and smaller, and at last the cells in which the bioplasts are dead scale off. When dead-never |