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been essentially due to the great incompleteness of our knowledge with regard to the intimate structure of our tissues wbich has continued to exist until quite recently, and, as we are sorry to be obliged to confess, still even now prevails with regard to many points of histology to such a degree that we scarcely know in favor of what view to decide. Especial difficulty has been found in answering the question from what parts of the body action really proceeds, what parts are active, what passive; and yet it is already quite possible to come to a definite conclusion upon this point, even in the case of parts the structure of which is still disputed. The chief point in this application of histology to pathology is to obtain a recognition of the fact that the cell is really the ultimate morphological element in which there is any manifestation of life, and that we must not transfer the seat of real action to any point beyond the cell.” And further on he said: “According to my ideas, this is the only possible starting-point of all biological doctrines. If a definite correspondence in elementary form pervades the whole series of all living things, and if in this series something else which might be placed in the stead of the cell be in vain sought for, then must every more highly developed organism, whether vegetable or animal, necessarily, above all, be regarded as a progressive total, made up of a larger or smaller number of similar or dissimilar cells. Just as a tree constitutes a arranged in a definite manner, in which, in every single part, in the leaves as in the root, in the trunk as in the blossom, cells are discovered to be the ultimate elements, so it is also with the forms of animal life. Every animal presents itself as a sum of vital unities, every one of which manifests all the characteristics of life. The characteristics and unity of life cannot be limited to any one particular spot in a highly developed organism (for example, to the brain of man), but are to be found only in the definite, constantly recurring structure, which every individual element displays. Hence it follows that the structural composition of a body of considerable size, a so-called individual, always represents a kind of social arrangement of parts, an arrangement of a social kind, in which a number of individual existences are mutually dependent, but in such a way that every element has its own special action, and, even though it derive its stimulus to activity from other parts, yet alone effects the actual performance of its duties. I have therefore considered it necessary, and I believe you will derive benefit from the conception, to portion out the body into cell-territories (Zellenterritorien). I say territories, because we find in the organization of animals a peculiarity which in vegetables is scarcely at all to be witnessed, namely, the development of large masses of so-called intercellular substance. Whilst vegetable cells are usually in immediate contact with one another by their external secreted layers, although in such a manner that the old boundaries can still always be distinguished, we find in animal tissues that this species of arrangement is the more rare one. In the often very abundant mass of matter which lies between the cells (intermediate, intercellular substance), we are seldom able to perceive at a glance how far a given part of it belongs to one or another cell; it presents the aspect of a homogeneous intermediate substance. According to Schwann, the intercellular substance was the cytoblastema, destined for the development of new cells. This I do not consider to be correct, but, on the contrary, I have, by means of a series of pathological observations, arrived at the conclusion that the intercellular substance is dependent in a certain definite manner upon the cells, and that it is necessary to draw boundaries in it also, so that certain districts belong to one cell, and certain others to another. You will see how sharply these boundaries are defined by pathological processes, and how direct evidence is afforded, that any given district of intercellular substance is ruled over by the cell which lies in the middle of it, and exercises influence upon the neighboring parts.

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“It must now be evident to you, I think, what I understand by the territories of cells. But there are simple tissues which are composed entirely of cells, cell lying close to cell. In these there can be no difficulty with regard to the boundaries of the individual cells, yet it is necessary that I should call your attention to the fact that, in this case, too, every individual cell may run its own peculiar course, may undergo its own peculiar changes, without the fate of the cell lying next to it being necessarily linked with its own. In other tissues, on the contrary, in which we find intermediate substance, every cell, in addition to its own contents, has the superintendence of a certain quantity of matter external to it, and this shares in its changes, nay, is frequently affected even earlier than the interior of the cell, which is rendered more secure by its situation than the external intercellular matter.

"Finally, there is a third series of tissues, in which the elements are more intimately connected with one another. A stellate cell, for example, may anastomose with a similar one, and in this way

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a reticular arrangement may be produced, similar to that which we see in capillary vessels and other analogous structures. In this case it might be supposed that the whole series was ruled by something which lay, who knows how far off; but upon more accurate investigation, it turns out that even in this chainwork of cells a certain independence of the individual members prevails, and that this independence evinces itself by single cells undergoing, in con. sequence of certain external or internal influences, certain changes confined to their own limits, and not necessarily participated in by the cells immediately adjoining."

Now, according to Heitzmann, what Virchow asserts of " a third series of tissues" is really true of all tissues. According to Heitzmann, not only are there contained no "cells" as isolated indi. viduals in any tissue of the body, but no tissue in the body is isolated from the others. He prefers not to use the term "cells;" he speaks of “living matter," and this he asserts is continuous throughout the whole body. If we desire to retain the use of the word cell to designate the living tissue-elements, we must regard each cell to contain a network of living matter within it, and every cell connected by threads of living matter with every other cell in its neighborhood; so that, to use Heitzmann's words: “The animal body as a whole is a connected mass of protoplasma in which, in some part, are embedded isolated protoplasma-corpuscles (wandering corpuscles, colorless and red blood-corpuscles), and various not-living substances (glue-giving and mucin-containing substances in the widest sense, also fat, pigment granules, etc.)."?

In contradistinction to the cell-doctrine, this might be termed the protoplasma doctrine; but as the word protoplasma is etymo. logically incorrect for designating living and formative matter, as it has already been used by some authors with a meaning other than the simple one here intended, and as it has not yet become so common that its retention or rejection is a matter of much con. sequence, I propose the designation bioplasson doctrine.3

I Cellular Pathology as based upon Physiological and Pathological Histology. By Rudolf Virchow. Translated from the 2d edition by Frank Chance, B.A., M.B. Cantab, etc. New York: Robert M. Devitt, pp. 29, 40, et seq.

? Untersuchungen über das Protoplasma. Von C. Heitzmann. Sitzungsbericht de K. Akad. der Wissenschaften. Band. Ixvii. Abth. iii. Mai-Heft, 1873, p. 15.

3 The word plasma (vò Thágua) really means the formed, that which is formed, and plasson (adáscov) the forming, that which forms or does the forming. The distinction is the one so justly insisted upon by Beale in his discrimination between germinal or living matter and formed material. The term plasma may, per

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If the lowest form of animal life, a so-called amaba, be examined with high magnifying power, a power of say 800 or 1000 diameters, it is seen to contain a network of threads crossing each other at various angles, the points of intersection being thickened into granules. During locomotion a protrusion is projected in which the network, sometimes at first plainly visible, becomes more and more fine until it seems to disappear; at the same time in the interior the threads can be seen to have shortened, and the granules to have come nearer together and to have enlarged; then the granules seem to flow toward or into the protrusion, the network is again plainly visible through the whole body, and locomotion is accomplished. Frequently vacuoles are seen; sometimes a granule is floating in a vacuole, and occasionally such a granule seems to send out threads which, when they touch the edges of the vacuole, cause the vacuole to disappear abruptly, whereupon the network

haps, be appropriately applied to the material formed from the fluid of living matter, the intermediate or intercellular substance of authors; but the term plasson only can be applied to active, living, forming matter. Proto ( 79 poros) is a prefix signifying first, primary, primordial; and protoplasma has been used by some to depote the original or first-formed organic matter. But the terin we are in need of for our biological doctrine is one that shall be an expression for living formative matter in its simple elementary form ; and for this purpose, it seems to me, bioplasson may appropriately be chosen. We must agree to denote by it not living matter in general, but specifically only the elementary form of living matter; and only this living matter, as such, i.e. while it is alive. On the last point I may quote a paragraph from an introductory lecture entitled “The Protoplasm Theory," delivered at the College of Physicians and Surgeons, New York, Oct. 1, 1873, by Prof. Edward Curtis. I quote verbatim except that I put the word bioplasson for the word protoplasm wherever it occurs in the paragraph.

“But here allow me a word to save you from possible confusion of thought. Observe that the term 'bioplasson’ is applied only to the living matter as such, while possessed of the physical and vital characteristics peculiar to its condition; it is not the name of the albuminoid compound or compounds into which chemical analysis can resolve the living mass. The two conceptions are distinct, and are to each other as those of diamond and carbon. Diamond is wholly composed of carbon ; yet while carbon is the chemical element wherever and however occurring, alone or in combination, diamond is the distinct thing—the gem-substance, as such, characterized by peculiar lustre, transparency, hardness, and planes of cleavage. Disturb the crystalline condition that determines these physical attributes of the mineral, as by heating diamond, protected from the air, between the poles of a powerful battery, and though its chemical composition is unchanged, yet the dull black mass into which the glittering jewel is transformed is, it is needless to say, no longer diamond. In other words, diamond is the mineralogist's name for the crystalline gem, and carbon the chemical designation of the matter that composes it. So with bioplasson ; the word belongs not to the chemist as meaning a product of analysis, but to the biologist as the name of a living thing."

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is again seen. The living amoeba consists of two constituents, a semi-solid, which is living matter, and a fluid which is not living. (See Fig. I.)

Let us with a similar high magnifying power examine a drop of blood, taken say from our thumb, upon the heated stage. At the ordinary temperature of the room, the shining colorless blood-corpuscles show no structure. When the temperature is gradually raised to 86° F. the following is seen. In the centre of the corpuscle one or two dull grayish, opaque homogeneous little bodies appear. From each of these radiate conical spokes passing into a net-work which extends through the whole corpuscle, and the nodal points of which appear thickened or as granules. At the periphery of the corpuscle the network seems closed by a continuous dull shining layer. The central body, spokes, threads, and granules seem optically similar; the meshes appear as light structureless spaces. While the temperature gradually rises to 95° F., changes of form occur continually, in the central body, as well as in the meshwork of the corpuscle, and in the latter itself. The central body is changed in varying places into a meshwork; in the rest of the cor. puscle there appear and disappear groups of larger granules with no, or very small, meshes. The groups change shapes, new ones take their places, and this play continues, even if the temperature falls again. When the temperature had fallen to about 74° F., there appeared in a colorless blood-corpuscle a vacuole, in which a loose granule executed slight pendulous movements. The granule was observed to change its form and to project from time to time thin threads, which disappeared again: once it seemed as though three particularly long threads were seen to reach to the wall of the vacuole suddenly the vacuole disappeared. Afterward a new vacuole arose at almost the same place, also containing a granule; but this vacuole became biscuit-shaped and enlarged by the breaking down of the partition wall of a neighboring vacuole. The whole blood-corpuscle gradually became full of vacuoles, though it still sluggishly changed its form. (See Fig. II.)

While the temperature was being raised (before reaching 86° F.), there frequently appeared in a blood-corpuscle a small, dark colored vesicular nucleus, containing one or two nucleoli. Such nuclei would sometimes appear at several points of the corpuscle while the temperature was rising. Heitzmann says they would originate under his eyes out of dull, grayish, compact bodies devoid of dark contour. In addition to larger dark-contoured nuclei—as many as

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