EXPERIMENTAL. MICROSCOPY—SOMMERS:. 83: 
study from the time, 1672, when Regnerus. De-Graaz applied the. 
Microscope to its elucidation. 
The infusoriz, so called, are very interesting to the Microsco- 
pist. The multitude of forms, variety of structure, uncertainty 
of the position of many of them, whether they belong to the 
animal or vegetable kingdom, inerease their value as objects for: 
study. They afford an immense field for original research, but 
partly explored. Here we find the battle ground where. Vitalist, 
Evolutionist and Panspermatist cam wage intellectual warfare. 
The Microscope has, rendered invaluable service in exploding: 
false ideas and crude theories. If we take for example the spon- 
taneous generation theory. Assuming all animals, the mode of 
whose generation is unknown or obscure, owe their origin to the 
spontaneous efforts of nature acting by force upon inorganic 
matter, the extent of its application would be proportionate to, 
the sum of our knowledge of sexual generation, or of generation. 
by division ; hence, in looking backward at the history of this 
theory, we find it always resting on an ever shifting base; accept- 
ed by the ancients, it sufficed to explain the generation of reptiles, 
fishes, insects, and all animals of whatever kind, whose mode. 
of re-production was unknown. 
The study of the embryology of these creatures have satisfied all 
doubts relative to their re-production, yet are we very much in 
the position of the scientific world in the time of Aristotle, 
heterogeny is still received by many as a scientific fact, the base 
being shifted to a still lower stratum of life, where the process of 
reproduction is obscure or not yet known. The question then 
arises, have we really a spontaneous origin of minute beings; or 
is there a possibility of the existence of a process of generation 
amongst them, of which we are ignorant? We are, so far as this 
question extends, in the position of our predecessors, previous to. 
the discovery of the Microscope. We cannot account for the ex- 
istence of a’Bacterium by reproductive generation, therefore it is 
generated spontaneously, if so, why not a snake? as Kercher be- 
lieved. Writing to Redi, he gives the following recipe for manu- 
facturing snakes :— 
“Take some snakes, of whatever kind you want, roast them, 
6 
