teria, presenting most rapid progressive movements accompanied by quick axial rotations. Many Torula corpuscles and other Fungus "spores" also existed, as well as portions of a mycelial filament containing equal segments of colorless protoplasm within its thin investing membrane.
A drop of the fluid containing several of these active Monads was placed for about five minutes on a glass slip in a warm-water oven maintained at a temperature 140° Fahr. All the movements of the Monads ceased from this time, and they never afterward showed any signs of life.
These experiments are two of the most remarkable selected from several others in which even higher temperatures were originally had recourse to in order to free the fluids and flasks generally from any thing like a trace of living matter. Nothing, that has yet been alleged by way of objection to the admission of "spontaneous generation" as an every-day fact, at all affects such experiments as these. The shortest way out of the difficulty would therefore be to doubt the facts. I can assure the reader, however, that they are as true and just as reliable as those other results obtained when working with lower temperatures, which, though strongly disbelieved in at first, are now generally recognized as trustworthy. And, although these now accredited results abundantly suffice, in face of our present knowledge concerning the limits of vital resistance to heat, to establish the strongest probability of the occurrence of "spontaneous generation," yet such experiments as those which I have now recorded even still further confirm this view, since it becomes incredible that, while all known forms of living matter with, which accurate experiment has been made inevitably perish at or about 140° Fahr., the particular examples of the same forms which appear within our sealed flasks have been able to survive a much longer exposure to 270°-275° Fahr. If this were true, then indeed would the cultivation of Science be a vain pursuit—"uniformity," in fact, must be postulated and granted, or Science with humbled and sorrowful crest must retire from the field.
A word or two must be said in conclusion with reference to the interpretation which should be attached to such experiments as those just recorded. And this subject cannot be better introduced than by means of the following extract from the already-quoted and valuable paper by Prof. Jeffries Wyman. He says: "There can therefore be no certainty of the existence of spontaneous generation in a given solution, until it can be shown that this has been freed of all living-organisms which it contained at the beginning of the experiment, and kept free of all such from without during the progress of it. On the other hand, this kind of generation becomes probable, whenever it is made certain that Infusoria are generated in solutions in which the conditions just mentioned have been complied with. We say prob-
