This work is an account of experiments conducted by Henry Charlton Bastian to challenge the doctrine of Louis Pasteur which states that those organisms which serve to initiate the fermentative modifications, have been derived from a multitudinous army of universal atmospheric germs, which are always prepared, in number and kind suitable for every emergency. It was his attempt at presenting the errors of reasoning M. Pasteur had fallen, and also how his findings were capable of being reversed by the employment of various experimental materials, and methods. Bastian was an advocate of the doctrine of archebiosis and believed that he witnessed the spontaneous generation of living organisms out of non-living matter under his microscope. Contents Include: Homogenetic Mode of Origin of Bacteria and Torulae Heterogenetic Mode of Origin of Bacteria and of Torulae Origin of Bacteria and of Torulæ by Archebiosis Comparative Experiments