Chapter V 

 NUTRIENTS 



Unlike animal tissue cultures, plant tissue cul- 

 tures have from the beginning been carried out in 

 nutrients which are wholly or in major part syn- 

 thetic. This is, of course, of great practical as 

 well as theoretical importance. Nevertheless, it 

 has come about as a matter of necessity rather 

 than by deliberate intent. Animal tissue culture 

 nutrients are for the most part made up of com- 

 plex organic materials — embryo extract (Carrel, 

 1913, 190), blood plasma or serum (Harrison, 

 1907, 131; Erlichman, 1935, 147), peptic digests 

 of fibrin (Baker, 1933, 183; Baker and Carrel, 

 1926, 184, 185, 1928, 187-189; Carrel and Baker, 

 1926, 191 ; Ebeling, 1921, 192, 1924, 193 ; Fischer 

 and Demuth, 1928, 194), tissue broth and the like 

 with, it is true, salt mixtures such as Ringer's 

 (1886, 160), Tyrode's (1910, 161), Locke's (1895, 

 157-159), or other solutions (Drew, 1922, 145, 

 1924, 146 ; Lewis, M. R., 1916, 148 ; Lewis, M. R., 

 and Lewis, W. H., 1911, 149-151, 1912, 152, 153; 

 Lewis, W. H., 1921, 154, 1923, 155, 1929, 156; 

 Vogelaar and Erlichman, 1933, 162, 1934, 163, 164, 



