always in a kind of trance. I know nothing in art that moves me as much as the Unseen Holy suggested before that picture.

Will you follow me long enough to-day, my friends, to find out that this Madonna di San Sisto of Raphael, whose interior suggests an ineffable exterior, is a true analogue of the cell,- God and the soul without, inert matter within, — every movement of the latter pointing to the former as its only adequate cause. Come near enough to this Madonna painting of Almighty God, and you will be convinced that it was the purpose of the Artist to make the interior suggest the ineffable exterior. [Applause.]

When we study living matter with the highest powers of the microscope, and under the lead of the best original investigators, what does the latest science see?

1. That nothing that lives is alive in every part. 2. That the substance of every living organism consists of three parts,

(1.) Nutrient matter, or pabulum.

(2.) Germinal matter, or bioplasm.

(3.) Formed matter, or tissue, secretion and deposit.

As you stand on some murmurous shore of a tropical sea, and pick up a beautifully colored shell, with its occupant yet in it, you easily perceive a difference between the living and the not-living part of that organism. No doubt the shell grows; and yet, even while the animal bears it about upon his back, parts of the shell are as truly inanimate as they are when

afterward the painted wonder lies on the shelf of your cabinet. The shell grows, but not in every part, if it be of mature size. It increases its bulk chiefly by additions of matter at its edges and on its interior; and these increments are made by a process of growth in the softer parts of the organism. We ourselves do not carry very large shells about upon our persons; but the finger-tips are incased in delicate shells, of which by no means every particle is living. It once has been living; but when you pare matter away from the back of a shell, or from the edge of the finger-nail, you find a very great distinction between it and the quick flesh that is touched in a nerve. Four-fifths of the bulk of most organisms, animal and vegetable, is made up of formed matter. Only one-fifth is really alive.

Into the centre of every organic cell there flows a current of nutrient matter, or pabulum; and this may be wholly inorganic. It may be gas; it may be a mineral compound; it may be formed material from meats and fruits. In a cell [referring to a figure the speaker drew upon the blackboard] this nutrient matter is first transformed into living matter, and next the living matter is thrown off as formed material, to make the cell-wall. There are two currents in an organic cell, - one flowing inward, and conveying nutrient matter with it; the other outward, and bearing with it formed material.

In the centre of the cell, by a process that cannot be explained by chemistry or any physical science, the nutrient matter is changed into living matter.

At the outer edge of the cell, formed material accumulates, and is in some cases tissue, in some secretion, in some an osseous deposit.

You have now, I hope, gentlemen, a distinct idea of the three kinds of matter which are to be found in all living organisms, - pabulum or nutrient matter, bioplasm or germinal matter, tissue or formed. matter. There are no living organisms, vegetable or animal, that are not made up wholly of these three kinds of matter.

It is only within a comparatively few years that we have been able to demonstrate under the microscope the existence of this distinction between the inner portions of the cell and the cell-wall. Why, Professor Huxley himself, down to 1853, considered the core of the cell as of little importance, and as having no peculiar office ("The Cell-Theory," Medical Chir. Rev., October, 1853). He has changed his opinion now on that point, as on several others concerning the cell-theory; and this fact is not to his discredit at all, because the microscopial study of living matter is advancing so rapidly, that theories of 1850 and 1860 must often be abandoned.

Professor Lionel Beale, who is an accepted authority as to this class of facts, however much his inferences, which I do not now present to you, may be objectionable to materialists, has made large use of a most important process of staining living tissue by a solution of carmine in ammonia. That particular solution makes red whatever is living in a tissue, and does not color formed material. When you drench a tis

sue in that solution of carmine in ammonia, you take it out with all the bioplasts stained red. This discovery has been a source of great advances in our knowledge of living tissues, so many of the ultimate parts of which are colorless, and as difficult as water to dissect optically. Fastening the highest magnifying power upon tissue prepared by this carmine process, what do we see?

3. That germinal points, or bioplasts, are scattered so pervadingly through all organic structures that in no organism is there a space one five-hundredth of an inch square without a germinal point, or bioplast.

We are sure to find, in any piece of living matter of that size, a bioplast that will color red in a solution of carmine in ammonia.

4. That the germinal points, or bioplasts, are the only living matter.

5. That all formed matter has once been living matter, and so differs totally from inorganic matter.

Every particle of your oyster-shell has once been living, growing matter, although it now is dead; and yet, although inanimate, it is not inorganic. The shaggiest back of an oyster is matter of a totally different kind from that of the sand and clay and. pebbles of which it makes a couch. Every particle of your muscle, nerve, or bone, has once been a bioplast.

I use the word "bioplasm" instead of "protoplasm," because it is a more definite term. It means always that germinal substance which has the power of transmuting not-living into living matter, and of movement,

of self-multiplication, and of producing formed material. "Protoplasm " is a word that has been applied to so many different styles of matter, that its indefiniteness in present usage is a frequent source of confusion of thought in biological discussions. "Bioplasm and "bioplasts" are words which agree well with biology," the accepted name of one of the greatest of the sciences.

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6. That in the cell of an organic tissue the central portion is always a bioplast.

7. That nutrient matter for the bioplasts may consist of inorganic matter, or of formed matter.

8. That the bioplasts convert the nutrient into living matter, and the living into formed matter.

9. That the transmutation of the not-living into the living occurs in the bioplasts instantaneously.

You will read in the older physiologies that all tissues are made up of cells; and that is, of course, true; but you must not suppose that it is the latest doctrine that the cell is the object of supreme interest in living tissue. The cell-wall is formed matter. The bioplast is the unit of growth. Bioplasm may exist without an enveloping wall. It may be a bioplast, and not a cell. You may have expected me to say much about cells and the cellular theory; and I am talking about bioplasts and the bioplasmic theory The theory of bioplasts has superseded the theory of cells, or rather has given to the latter more definiteness; so that now we speak of cells with meanings derived from bioplasts.

10. That the cell-wall is formed matter, and not