Just above the creature, which was resting in its tube (it builds a gelatinous tube into which it shrinks when alarmed or disturbed in any way), there was a bit of alga, from which ripened spores were being given off. Some of these spores were ruptured (probably by my manipulations) and starch grains were escaping therefrom.
The Stentor, from its location below the alga, could not reach the starch grains without altering its position. I saw it elevate itself in its tube until it touched the starch grains with its cilia. With these it swept a grain into its mouth, and then sank down in its tube. I thought, at first, that this was the result of accident, but when the creature again elevated itself, and again captured a starch grain, I was compelled to admit design!
By some sense, it had discovered the presence of starch, which it recognized to be food; it could not get at this food without making a change in its position, which, therefore, it immediately proceeded to do!
Here was an act which required, so it seemed to me, correlative ideation, and which was doubly surprising, because occurring in an animal of such extremely simple organization. This observation was substantiated, however, by the testimony of Professor Carter, an English biologist, which came to my notice a week or so thereafter. This investigator witnessed a similar act in an animalcule belonging, it is true, to another family, but which is almost, if not quite, as simple in its organization as Stentor. He does not designate the particular rhizopods that he had under observation, yet from his language, we are able to classify them approximately. His account is so very interesting that I take the liberty of quoting him in full.
"On one occasion, while investigating the nature of some large, transparent, spore-like elliptical cells (fungal?) whose protoplasm was rotating, while it was at the same time charged with triangular grains of starch, I observed some actinophorous rhizopods creeping about them, which had similar shaped grains of starch in their interior; and having determined the nature of these grains by the addition of iodine, I cleansed the glasses, and placed under the microscope a new portion of the sediment from the basin containing these cells and actinophryans for further examination, when I observed one of the spore-like cells had become ruptured, and that a portion of its protoplasm, charged with the triangular starch grains, was slightly protruding through the crevice. It then struck me that the actinophryans had obtained their starch grains from this source; and while looking at the ruptured cell, an actinophrys made its appearance, and creeping round the cell, at last arrived at the crevice, from which it extricated one of the grains of starch mentioned, and then crept off to a good distance. Presently, however, it returned to the same cell; and although there were now no more starch grains protruding, the actinophrys managed again to extract one from the interior through the crevice. All this was repeated several times, showing that the actinophrys instinctively knew that those were nutritious grains, that they were contained in this cell, and that, although each time after incepting a grain it went away to some distance, it knew how to find its way back to the cell again which furnished this nutriment.
"On another occasion I saw an actinophrys station itself close to a ripe spore-cell of pythium, which was situated on a filament of Spirogyra crassa; and as the young ciliated monadic germs issued forth one after another from the dehiscent spore-cell, the actinophrys remained by it and caught every one of them, even to the last, when it retired to another part of the field, as if instinctively conscious that there was nothing more to be got at the old place.
"But by far the greatest feat of this kind that ever presented itself to me was the catching of a young acineta by an old sluggish amœba, as the former left its parent; this took place as follows:
"In the evening of the 2d of June, 1858, in Bombay, while looking through a microscope at some Euglenæ, etc., which had been placed aside for examination in a watch-glass, my eye fell upon a stalked and triangular acineta (A. mystacina?), around which an amœba was creeping and lingering, as they do when they are in quest of food. But knowing the antipathy that the amœba, like almost every other infusorian, has to the tentacles of the acineta, I concluded that the amœba was not encouraging an appetite for its whiskered companion, when I was surprised to find that it crept up the stem of the acineta, and wound itself round its body.
"This mark of affection, too much like that frequently evinced at the other end of the scale, even where there is mind for its control, did not long remain without interpretation. There was a young acineta, tender and without poisonous tentacles (for they are not developed at birth), just ready to make its exit from its parent, an exit which takes place so quickly, and is followed by such rapid bounding movements of the non-ciliated acineta, that who would venture to say, a priori, that a dull, heavy, sluggish amœba could catch such an agile little thing? But the amœbæ are as unerring and unrelaxing in their grasp as they are unrelenting in their cruel inceptions of the living and the dead, when they serve them for nutrition; and thus the amœba, placing itself around the ovarian aperture of the acineta, received the young one, nurse-like, in its fatal lap, incepted it, descended from the parent, and crept off. Being unable to conceive at the time that this was such an act of atrocity on the part of the amœba as the sequel disclosed, and thinking that the young acineta might yet escape, or pass into some other form in the body of its host, I watched the amœba for some time afterwards, until the tale ended by the young acineta becoming divided into two parts, and thus in their respective digestive spaces ultimately becoming broken down and digested."[31]
In the discussion of conscious and unconscious mind, I called attention to the marginal bodies of the nectocalyx of the jelly-fish. These bodies in the "covered-eyed" species are protected by hoods of gelatinous tissue; in the naked-eyed species the hoods are absent. The marginal bodies in both species are practically identical as far as general make-up is concerned, being composed of an accumulation of brightly-colored pigment-cells, embedded in which are several minute clear crystals. Nerve-fibres connect these bodies with the sensorium ("nerve-ring").