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RED I; TUBERVILLE NEEDHAM. 119similar jars of meat left purposely uncovered. Substituting fine gauze forthe paper coverings, the flies were soon attracted by the emanating odour,but being unable to get at the meat deposited their eggs upon the gauze,and out of which eggs minute maggots were then seen to develop. Thisvery simple experiment by which Redi proved his case, carries with it, aspresently shown, a most practical and important bearing upon the questionof spontaneous generation in the modern acceptation of the term. Theweapon, however, that proved of the greatest service at about this sameepoch in breaking down the ancient superstitions concerning the spontaneousgeneration of highly organized animals, was undoubtedly the microscope,now utilized for the first time in unravelling the mysteries of nature.With this instrument in the hands of Leeuwenhoek, Robert Hooke,Hartsoeker, and other early labourers,it was soon discovered that the hithertodeemed doubtful or spontaneously multiplying species propagated theirkind perpetually through the medium of impregnated seeds or eggs, afterthe manner of the larger and more familiar types, and the idea of spontaneousgeneration, so far as such organisms was concerned, was banishedto oblivion. The agency, however, which thus achieved the overthrowof this theory in one direction, paved the way for its re-establishmentin another, and as it at first seemed, on an apparently far more sure andsubstantial basis.Among the most important revelations of the hitherto invisible andunknown world made known with the assistance of the microscope, wasundoubtedly the discovery by Leeuwenhoek, in the year 1676, of the microscopicbeings that form the subject-matter of this volume. The abundantconfirmation of this discovery and the intense interest manifested on allsides in so newly indicated and fascinating a field of research, necessarilyentailed a speedy recognition of the extraordinary rapidity with which theseminute organisms multiplied, and also of their appearance suddenly in vastnumbers under auspices totally at variance with the propagative phenomenaof all previously known organic forms. None of the then familiar laws oforganic reproduction sufficing to explain these several phenomena, the mindnaturally reverted to that interpretation of the "incomprehensible" initiatedby the philosophers of antiquity, and stamped such abnormal manifestationswith the brand of the miraculous.As indicated in a preceding chapter, the theory of abiogenesis or spontaneousgeneration, as applied to the minute animalcules produced soabundantly in infusions, took its origin as a possible hypothesis with theirfirst discoverer, and was upheld with more or less force by Gleichen, Joblot,and O. F. Miiller. The first, however, to mould this somewhat vagueidea into shape and to formulate out of it that definitive doctrine concerningthe spontaneous production of the lowest organisms that withvarying fortune has commanded adherents thenceforward up to the presenttime, was undoubtedly our own countryman Tuberville Needham, who inhis ' New Microscopical Discoveries,' printed in the year 1745, and various