EVOLUTION THE MASTER-KEY 



that, if boiling be not performed, but merely filter- 

 ing through a germ-proof filter, the result (the non- 

 development of life) would be conclusive; but it 

 has been shown that such filtration alone suffices 

 to alter the chemical nature of the filtered fluid. 

 " Spontaneous generation" is not, therefore, proved 

 to be a myth even by this experiment. So much 

 for destructive criticism. 



But Dr. Bastian has also positive results to of- 

 fer. He has seen, he tells me, the development, 

 in a previously clear fluid, of minute black spots, 

 which gradually enlarge, and at last become motile 

 bacteria. This change cannot successfully be re- 

 corded ; but it seems to me to be not inconceivable 

 that a cinematographic apparatus might be ad- 

 justed to the microscope, and thus demonstrate, 

 beyond all cavil, the evolution which Dr. Bastian 

 declares that he has seen. 



The most remarkable photograph that Dr. Bas- 

 tian has taken shows the spines, magnified seven 

 hundred times, of a minute water-animal known as 

 the Cyclops. In these spines, which are absolutely 

 impervious to the smallest known organisms, there 

 develop a number of spots, which finally are rec- 

 ognizable as bacteria. This his photographs clear- 

 ly show. Either these bacteria have arisen de novo 

 in the tissue of the spine, or they are the en- 

 larged forms of some bacteria, hitherto unknown, 

 which are too small for the microscope to detect 

 are ultra-microscopic and which have somehow 

 made their way through the tough covering of the 



