HISTORY OF BACTERIOLOGY 
The science of Bacteriology is still young, and like 
normal youth is marked by constant, vigorous growth, 
yet the micro-organisms with which it deals are veri¬ 
tably antique, for the following quaint observation is 
said to have been made two thousand years ago: “It 
is to be noticed that if there be any marshy places, 
certain animals breed there, which are invisible to the 
eye and yet, getting into the system through the mouth 
and nostrils, cause serious disorders.” 
Later on when the early scientists were looking 
through their very imperfect lenses at certain liquids, 
they saw many hardly visible moving bodies. They 
said, “Surely these moving things must be alive,” and 
as they had not put anything into the liquids, it was 
natural to conclude that the little forms must have 
been spontaneously generated. So great a thinker as 
Aristotle had previously made a similar statement, for 
when he saw birds one morning flying about over the 
valley of the Nile, where the day before not a bird 
was present, he devoutly concluded that they must 
have been generated from the mud of the Nile, that 
great Father of Plenty. It is within the memory of 
some living today that this theory of spontaneous 
generation was still believed. 
About 1675 Leuwenhock, the son of a Dutch lens 
grinder, saw through one of his lenses in a drop of 
stagnant water minute moving forms. Soon some of 
the scientists became interested and studied these “ani¬ 
malcules” or little animals, as they were called. They 
Spontaneous 
Generation 
of Life 
Animalcules 
109 
