WHAT IT IS AND WHAT IT IS NOT. 71 
neous generation. There is no necessary connection 
between the one theory and the other. Spontaneous 
generation, or birth without parentage, on the part of 
small or useless creatures was accepted 
in early times without question. As men 
began to observe these animals more 
carefully, the fact of their spontaneous generation was 
doubted. A great step was made when it was found 
that to screen meat from flies would protect it from 
maggots. A greater step came in our own time when it 
was proved that to screen infusions from air dust is to 
protect them from putrefaction or fermentation. Fer- 
mentation is “ life without air.” It is the decomposition 
of sugar by minute creatures who disintegrate it in their 
life processes. Putrefaction and decay are also the 
same in nature. There is literal truth in Carlyle’s state- 
ment that there is still force in a fallen leaf, “else how 
could it rot?” It is the force of the minute organisms 
hidden in the leaf, and whose life is the leaf’s decay. 
The decay and death of men from contagious diseases 
are known to be due to life processes of minute organ- 
isms, as is the gangrene which follows unskilful sur- 
gery. The study of the “fauna and flora” within living 
organisms has now become a science of itself, demand- 
ing the greatest care in observation and the most com- 
plete of appliances. ‘ Omne vivum ex vivo,” “all life from 
life,” was an aphorism of the naturalists of a century or 
two ago. It was to them a new and broad generali- 
zation. It has not yet been set aside. The classic ex- 
periments of Tyndall show that this law applies to all 
creatures we have yet recognised or classified. As far 
as science can tell, spontaneous generation is still a 
myth, having no basis in observation, no warrant in ex- 
periment. It remains as a pure deduction from the phi- 
losophical conception of Monism. It is incapable of 
Spontaneous 
generation. 
