HAECKEL AND PFLUGER 8l 



vapour and carbon dioxide. Osborn thought that this carbon 

 dioxide acted as the source of carbon for the formation of 

 those organic compounds from which living organisms later 

 de\'eloped. He wTote : 



We may advance the hypothesis that an early step in the 

 organization of living matter was the assemblage, one by one, 

 of several of the ten elements now essential to life ... Of these 

 the four most important elements were obtained from their 

 previous combination in water (HoO), from the nitrogen com- 

 pounds of volcanic emanations or from the atmosphere consist- 

 ing largely of nitrogen, and from atmospheric carbon dioxide. 



However, Osborn did not give any explanation of the way 

 in which this sort of transformation came about. He confined 

 himself to rather vague statements about the ' attractive 

 force ' of oxygen and hydrogen. 



Similar views w^ere developed by W. Francis,^^ who 

 attached far greater significance to iron in the process of the 

 formation of life, and by many other authors in the first 

 quarter of this century. It is characteristic of most of these 

 authors that they were convinced that living things developed 

 directly from lifeless matter as a restdt of the formative 

 activity of some external force. 



The practical outcome of all these hypotheses was the 

 carrying out of experiments in which the forces which were 

 supposed to have given rise to life in the past ^vere repro- 

 duced in the present under laboratory conditions. However, 

 as was to be expected, these experiments did not meet with 

 success and are now completely forgotten. Only a few of the 

 more typical investigations w411 be discussed here. 



R. Dubois^® placed pieces of radium or barium chlorides 

 on the surface of a sterile gelatin broth, and, according to 

 his o^vn account, he obtained microscopic granulations 

 resembling colonies of microbes. They moved actively, giew^ 

 and divided but cotdd not be subcultured on sterile portions 

 of the broth. 



Similar experiments were ptiblished somewhat later by 



M. Kuckuck^^ under the grandiose title Losung des Problems 



der Urzeugung. According to the observations of this author, 



when radium acted on a mixture of gelatin, glycerine and 



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