252 LIFE AND DEATH. 



established fact that it is impossible for life to arise 

 from a concurrence of inorganic materials and forces. 

 This was the opinion of Ferdinand Cohn, the great 

 botanist ; of H. Richter, the Saxon physician, and of 

 W. Preyer, a physiologist well known from his 

 remarkable researches in biological chemistry. 

 According to these scientists, life on the surface of 

 the globe cannot have appeared as a result of the 

 reactions of brute matter and the forces that continue 

 to control it. 



According to F. Cohn and II. Richter, life had no 

 beginning on our planet. It was transported to the 

 earth from another world, from the cosmic medium, 

 under the form of cosmic germs, or cosmozoa, more 

 or less comparable to the living cells with which we 

 are acquainted. They may have made the journey 

 either enclosed in meteorites, or floating in space in 

 the form of cosmic dust. The theory in question 

 has been presented in two forms : — The Hypothesis of 

 Meteoric Cosinozoa, by a French writer, the Count 

 de Salles-Guyon ; and that of cosmic panspermia 

 brought forward in 1865 and 1872 by F. Cohn and 

 H. Richter. 



Hypothesis of the Cosiiiosoa. — The hypothesis of 

 the cosmozoa, living particles, protoplasmic germs 

 emanating from other worlds and reaching the earth 

 by means of aerolites, is not so destitute of probability 

 as one might at first suppose. Lord Kelvin and 

 Helmholtz gave it the support of their high authority. 

 Spectrum analysis shows in cometary nebulae the 

 four or five lines characteristic of hydro-carbons. 

 Cosmic matter, therefore, contains compounds of 

 carbon, substances that are especially typical of 

 organic chemistry. Besides, carbon and a sort of 



