138 B. T. LOWNE ON SO-CALLED SPONTANEOUS GENERATION. 



arise de novo, but rather by the aggregation, and after development 

 of existing germs or gemnmles. 



With regard to the experimental evidence, it has been arrived at 

 from two classes of experiments. 



The first aims at the production of known organic forms from 

 solutions of animal or vegetable matter. The second aims at the 

 production of new and unknown forms, under new conditions in saline 

 solutions. 



I shall consider these two sets of experiments separately. 



In the first, or simplest set of experiments, the most contradictory 

 evidence has been arrived at by different observers. The whole, to 

 my mind, may, however, be summed up in the following. 



If we receive the usually accepted belief that the boiling temper- 

 ature destroys germs, we must accept spontaneous generation as a 

 fact. If, on the other hand, we believe that germs are not killed 

 in this manner, these experiments only show that if the greatest 

 possible care is used, germs may not be admitted and a negative 

 result may be arrived at, and yet that germs may find their way 

 into the flasks of the most careful experimenter, and may after- 

 wards germinate. 



Now, sir, I have instituted a series of the most careful experi- 

 ments, which have shown conclusively to my mind that germs are 

 not destroyed by the boiling temperature. 



I took a neutral solution of acetate of ammonia and put into it a 

 number of spores of the little mould known as Penicillium glaucum, 

 and boiled them well. I then enclosed some of the boiled fluid and 

 germs in capillary glass tubes, like those used for preserving vaccine 

 lymph. I then carefully examined the tubes by scrutinizing them 

 with the microscope for an hour each, and not a spore had germi- 

 nated, not a mycelial filament existed in the tubes. I then put 

 the tubes into a warm place by the stove, and in twenty-four hours 

 numerous mycelial filaments of considerable length had protruded 

 fiom many of the spores. Now, gentlemen, I should think the 

 most hardy advocate of spontaneous generation would hardly assert 

 that these spores had originated de novo, and germinated in a single 

 night and day. 



To make the experiment more complete, I enclosed in another 

 tube some spores which had not been boiled, and I found about the 

 same number had germinated in this tube, as in those containing 

 the boiled spores. 



I have tried another set of experiments of a similar kind. I 



