
INTRODUCTION 
A? knowledge increases concerning any depart- 
ment of science it almost always becomes 
necessary to give up some terms or modes of 
expression that have been long in use; either because 
they convey notions ‘absolutely irreconcilable with 
the later development of knowledge, or because they 
are too vague and general. Hence it is that the 
phrase “‘ spontaneous generation” should be rejected 
at the present day. The phenomena hitherto re- 
ferred to under this name would be no more 
“spontaneous” than are any others which take 
place in accordance with natural laws. The phrase 
is, moreover, quite inadequate, since under it, if 
retained, we should have to include two sets of 
phenomena which, in the present day, ought to be 
carefully discriminated from one another. 
Many who have written on the subject of 
“spontaneous generation’ have, however, failed to 
appreciate the full extent of the difference that exists 
between the origin of living things from not-living 
materials (Archebiosis), and their production, in 
whatever fashion—whether by modes that are 
familiar or by others which are unfamiliar—from 
the substance of pre-existing living things. This 
difference, which is so little dwelt upon by some, 
assumes in the minds of others an overwhelming 
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