SPOFTANEO US GENERA TION. 



109 



THE GERM-THEORY AND SPONTANEOUS GENERATION. 



PASTEUR— TYNDALL— BASTIAN. 



ON almost all subjects it is pleasant to know 

 that, in spite of occasional fluctuations, 

 our acquaintance with Nature advances with a 

 steady pace. Science makes good her ground as 

 she marches forward from age to age. The con- 

 troversies of one epoch become the certainties of 

 the next. The errors of early investigators are 

 slain never to revive. The doubts and mists of 

 a tentative philosophy crystallize by degrees into 

 true principles of science, which evolve fresh 

 doubts and mists destined to be transformed in 

 their turn by the finer alchemy of a more in- 

 structed future. The most bigoted opponents of 

 modern inquiry give at this day a ready assent 

 to doctrines which were once denounced as dia- 

 bolical heresies. Even the pope would shrink 

 from cursing the memory of Galileo, and is forced 

 to yield a reluctant or unconscious homage to the 

 triumphant career of scientific truth. 



There is one seeming exception to this law 

 of continuous advance — one controversy which 

 has maintained itself in full vigor from the 

 earliest dawn of thought to its latest develop- 

 ment, and is at least as animated now as it has 

 been at any stage of the world's history. Thou- 

 sands of years ago men speculated with more or 

 less agreement on the mystery of the origin of 

 life, and though modern work has multiplied the 

 materials for speculation, it seems to have left us 

 as far as ever from agreement. No one, indeed, 

 doubts now that all the higher types of life with 

 which the earth teems have been developed by 

 the patient process of evolution from lower or- 

 ganisms, and in logical consistency we are bound 

 to trace back the series to the simplest forms of 

 protoplasm which the microscope reveals to us 

 as living units. But all this is but the outcome 

 of life from life, and leaves us without an ap- 

 proach to a solution of the mighty question of 

 the origin of life. There was a time when the 

 earth was a red-hot melted globe on which no 

 life could exist. In course of ages its surface 

 cooled ; but, to quote the words of one of our 

 greatest savants, " when it first became fit for life 

 there was no living thing upon it." How, then, 

 are we to conceive the origination of organized 

 creatures ? Did moulds and confervoid growths, 

 or some yet simpler primordial germs, spring 

 once for all into existence by a fiat of creative 



power to become the fruitful parents of all vege- 

 tal and animal life, or is the same law which 

 brought out of the dust of the earth the earliest 

 of its organic inhabitants still in operation, and 

 are we to imagine that the lowest organisms, con- 

 stantly being drafted into higher grades as the 

 work of evolution goes on, have their ranks as 

 constantly replenished by a fresh development 

 of life from the so-called dead materials of the 

 parent earth ? These are questions to which 

 a priori dreams can give no answer. According 

 to his temperament a man may feel, he knows 

 not why, impelled to prefer the one or the other 

 hypothesis. To one mind it seems easier to 

 fancy a single discontinuous effort of life-creating 

 power, while another rests more naturally in the 

 faith that the law of continuity which dominates 

 all other phases of Nature will ultimately come to 

 be accepted as indicating the unceasing operation 

 of the same agency which once, at any rate, must 

 have bridged over the gulf between living and 

 non-living matter. 



Thus scientific belief has come to be divided, 

 and, indeed, has almost always been divided, be- 

 tween two hypotheses : one — let us call it the 

 germ-theory — which declares that no life has ever 

 been evolved (except in the remotest periods of 

 the earth's history), otherwise than from a living 

 parent or a living germ ; the other, familiarly 

 though not very accurately styled the spontane- 

 ous generation theory, which declares that, now 

 as of old, life does also spring de novo from mo- 

 lecular rearrangements of the atoms of dead or- 

 ganic materials. 



The attitude of the one school has never been 

 more truly pictured than in the eloquent words 

 of Prof. Huxley, when, many years ago, he laid 

 before the British Association the tenets of 

 what he called, not his belief, but his philosophic 

 faith upon this matter : " If it were given to me 

 to look beyond the abyss of geologically recorded 

 time to the still more remote period when the 

 earth was passing through physical and chemical 

 conditions which it can no more see again than a 

 man can recall his infancy, I should expect to be 

 a witness of the evolution of living protoplasm 

 from not-living matter." The attitude of the 

 opposite school has often expressed itself in 

 some such shape as this : " I have no warrant 



