sistency, it appears to have become a confused mass, or an indurated green mucus. When the mass is broken and observed through a good microscope, the original green corpuscles appear again, but changed in form, enveloped in a slimy matter, and interwoven with small transparent threads resembling slender colourless glass tubes, and show irregular yet visible movements. They approach each other, return again to their former position, become entangled with each other, and again disentangle themselves. If observed at the instant when such movements occur with the greatest energy, these little filaments have all the appearance of diminutive eels; in fact they are in some degree similar to the small vermiculations observed in vinegar. We may often discover in them even peristaltic motions. The white colour and the motion of these filaments last but a certain time. After a few weeks more, the crust becomes more solid, uneven, and raised here and there into irregular protuberances. The threads (or filaments) become more distinct; they are green, and scattered about without order, chiefly on the most prominent part of the crust, without however rising over its surface, which remains smooth and rather hard to the touch. The crust itself presents scarcely any traces of the original animalcules.
"If the crust be left undisturbed, and the water be now and then, but seldom, renewed, the unevennesses of the crust increase and rise in a pyramidal form. As soon as the pyramids are formed, the green threads, winding irregularly through the unevennesses of the green crust, rise also, become developed, and dispose themselves along the pyramidal bodies, toward the upper parts of which they become particularly visible; the rest is of a gelatinous substance, of a sufficient consistence to maintain its form as long as it remains under water. If these productions belong to the class of zoophytes, they must be ranked among the Tremellæ."
Some have indeed denied the actual production of organized from unorganized matter, since distilled water over quicksilver does not produce any green matter. But in the first place it is not easy to see why a metamorphosis should not be regarded as such because it occurs only under certain given circumstances; in the second place, it is also very possible that in a process so little favoured even by pure water, the quicksilver, on account of its property of counteracting production (a property which renders it so useful as medicine), may destroy or prevent the infusorial fermentation, as it has been called.
We think therefore that we are not in error when (combining the consideration of these important changes with our general inquiries into unorganized matter,) we recur to the proposition we have before laid down, viz. that the multiplicity of the phænomena of nature rests upon one unity; that nature therefore nowhere presents either an absolute difference (for such changes would then be inexplicable), or an absolute identity; and consequently, if we give the name of sub-
