CHAPTER I 



CELLULAR TOPOCHEMISTRY 



It would be a grave mistake to believe, as is often stated, that the cellular 

 theory of life, as proposed by Theodor Schwann, was of a purely morpho- 

 logical character, Schwann not only affirmed that "Everything which lives 

 is made up of cells", but he also pointed out that the individual life of each 

 cell "has its origin in forces which are inherent in each molecule". For his 

 teacher Johannes Muller, the phenomena of life were the result of an idea 

 acting on each tissue producing in it a "vital energy". On the other hand, 

 Theodor Schwann stated that living phenomena are the product of forces 

 which are essentially the same as those present in inorganic nature, forces 

 acting blindly and compulsorily like physical forces. The forces which 

 bring about the formation of organisms, Schwann added, do not act in 

 non-living nature because the combinations of molecules which give rise 

 to them do not occur there. But, he added, it does not follow that it is 

 necessary to distinguish them from ordinary physical or chemical forces. 

 In his work Mikroskopische Untersuchungen, Schwann proposed the classi- 

 fication of tissues which is still to be found, without major alterations, in 

 text books of histology. But he was forced to watch in despair the develop- 

 ment along purely morphological lines of the microscopic anatomy which 

 he had founded. The never-ending controversies among the histologists 

 and cytologists over their artifacts of coloration and fixation were of no 

 interest to him. To Schwann, the pressing problem was the study, by 

 physical and chemical methods, of metabolism (using the word he had 

 created) of units smaller than the cell itself. But, he had arrived too 

 soon, in a world too immature and only capable of producing great numbers 

 of publications illustrated by beautiful colour pictures of tissues. This 

 enormous mass of literature has left us little else than the idea of the 

 presence in the cell of a nucleus containing a nucleolus, and a cytoplasm 

 in which one can distinguish the presence of mitochondria and other in- 

 clusions. Classical histology, as the fruit of a hundred years of tissue-sHcing, 

 fixing and staining, has provided us with a great number of pictures of 

 cells, pleasantly coloured with Janus green or gentian violet. Unfortunately 

 they bear no relation to the complex phenomena described, in an abbre- 

 viated and simplified form, in the preceding pages. One might as well try 



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