THE CELL 51 



From that time the study of the cell has 

 absorbed the attention of scores of workers 

 and especially of late years has developed 

 an enormous literature entirely its own. 

 Nor is this wonderful when one remembers 

 the remarkable results which have followed 

 upon this discovery. The theory, it may 

 fairly be said, first formally laid down as a 

 principle by Virchow in the work which re- 

 volutionised pathology is the foundation of all 

 modern knowledge in that subject. It was 

 through this discovery that the common plan 

 of organisation of plants and animals first 

 became evident. It is through it also that we 

 havi arrived at an understanding of the pro- 

 cesses of fertilisation and of development. It 

 is clear, therefore, as Wilson * says " that 

 the key to all ultimate biological problems 

 must, in the last analysis, be sought in the 

 cell." Von Bunge points out that it is no 

 simple exercise which we set ourselves when 

 we proceed to endeavour to unravel its mys- 

 teries. " When," he says, " with the help of 

 scalpel and microscope, we have dissected the 

 organism to its last shred, when we are con- 

 cerned only with the single cell then the 

 greatest riddle still lies before us. The single 



* Op. cit., p. 1. 



