SPONTANEOUS GENERATION" ( FROTOGENESIS) NECESSARY TO ACCOUNT FOR THE BEGINNINGS OF LIFE. Some of those who, like Wyman, made obser vations disproving its occurrence at the present day, yet supposed that in the beginning the first living organisms probably arose from inorganic matter, through the action of unknown physico chemical processes. Tn 1SOS Herbert Spencer, while the ancient doctrine of spon taneous generation, stated his belief that the formation of organic matter and the evolution of life in its lowest forms "took place at a time when the heat of the earth's surface was falling through ranges of temperature at which the higher organic compounds are unstable." He conceived that the molding of such organic mat ter must have begun with portions of protoplasm, more minute, more indefinite, and inure nu•on stant in their characters than the lowest rhizo pods, or even the Protogenes of Ilaeckel. With this view biologists are now in agreement.
It is evident that the earliei.t living organism appeared when the temperature of the earth's crust amt of the air and sea approached that which it is now; the earth's climate probably ex ceeded in temperature that of the present torrid zone; the sea may have been less saline; but we know that at present exceedingly few plants and animals can live in hot springs; that there is no life in our geysers, and, judging from analogy, the earth's surface inust have been nearly as it is now when the first bit of animated protoplasm came into being.
When the earth had assumed its present shape, with its incipient continents, and the oceans lying in their basins, the period arrived when the con ditions for the appearance of life became favor able, and at this critical moment the protoplasmic substance probably came into lwing. The chemi cal compounds giving origin to it were far more abundant. and the physical and chemical con ditions more favorable.
The origin of protoplasm was probably the re sult of a combination of circumstances which cer tainly never occurred before in the history of our planet, and which has never happened since. The phenomenon of protog,enesis, after taking place once for all, could never have again occurred.
Such is the nature of of sexual production, of growth, and of heredity, that it would he contrary to the course of nature to sup pose that it was ever afterwards necessary for it to again occur. After protoplasm appeared, the earth and ocean probably became tan coo] to sup ply a sufficiently high temperature, or chemical compounds of the right degree of stability to form protoplasm.