184 Plant Tissue Culture 



lems again passed to a third set of workers, where 

 Fell used it in studying bone-phosphatase activity 

 (Fell, 1928 et seq., 392-401), Warburg in studying 

 tumor metabolism (Warburg, 1923, 272, 1926, 273 ; 

 Warburg and Kubowitz, 1927, 274), Rivers in 

 growing vaccines (Rivers, Haagen, and Mucken- 

 fuss, 1929, 440, 441; Rivers and Ward, 1935, 

 442), etc. 



The plant tissue culture idea began with a 

 theory rather than with a specific problem. 

 Haberlandt's theory (1902, 98) gave rise to a 

 technique in the hands of Gautheret (1932 et seq., 

 48), White (1934 et seq., 65), and others. Being 

 of much more recent development than the animal 

 tissue culture technique, it has no such great 

 literature of applications, yet it has already found 

 a variety of fields of usefulness and will doubtless 

 find many more in the future. 



The applications of the tissue culture technique 

 fall for the most part in three fields : in physiology, 

 in pathology, and in morphogenesis. 



Physiology 



Gross reactions. As we have seen elsewhere, 

 that aspect of a culture's reaction to its environ- 

 ment which can be most easily recorded in quanti- 

 tative terms is its increase in mass. Its altera- 

 tions in form come second, while in the third rank 



