1 9 2 BA CTERIA NO T FORMED B Y COALESCENCE. 



was examined, at first appeared perfectly clear, but after- 

 wards it became crowded with living beings. How did they 

 come there ? It has been stated that simple organisms 

 such as those referred may spring up spontaneously ; but 

 this statement is met by very serious objections, if, indeed, 

 it is not contradicted by facts open to the observation of all. 

 The doctrine of spontaneous generation has again quite 

 recently been revived in England, but of course has been 

 again refuted by an overwhelming mass of evidence. 



It seems to me that the evidence in favour of the con- 

 clusion, that in no case are bacteria or any other organisms 

 formed by the aggregation and coalescence of particles of 

 lifeless matter, is as conclusive and as irrefragable as is the 

 evidence against any such mode of formation in the case of 

 plants or trees, elephants, or men. Vague statements about 

 the coalescence of molecules to form particles of proto- 

 plasmic matter, or a physical basis of life, are not convinc- 

 ing. Every one naturally inquires what is the nature of 

 the molecules alluded to, but he gets no sufficient answer. 

 Of the molecules in question, all, it may be admitted, are 

 complex, but the elements of which they consist must be 

 arranged in some very peculiar manner to constitute the 

 living form, but we are neither instructed concerning this, 

 nor informed what determines the new state of combination, 

 which must happen at the moment when the protoplasmic 

 substance comes into being. To any one who has actually 

 studied under the highest powers of the microscope (3,000 

 linear and upwards), the most minute living organisms, and 

 has watched their movements and growth, the statements 

 advanced in favour of spontaneous generation will appear 

 hardly worthy of serious discussion, because he will feel 



