The History of Plant Tissue Culture 35 



Bobbins and his coworkers on excised roots (Rob- 

 bins and Bartley, 1937, 170, 222, 223; Robbins, 

 Bartley, and V. B. White, 1936, 58; Robbins and 

 Schmidt, 1938, 60, 1939, 61, 224, 225 ; Robbins and 

 V. B. White, 1936, 62) stem largely from these 

 studies of 1930-1934. It is this work since 1930 

 which forms the basis for the present volume. 

 The field is still too new to be frozen into definite 

 patterns. This account merely attempts to bring 

 it as nearly up to date as possible and to make the 

 present techniques available to students of the 

 field. 



Summary 



The history of plant tissue culture has been a 

 long and tenuous one. It may be conveniently 

 divided into four periods: 1834-1900 — The con- 

 cept of cellular totipotency and its demonstration 

 by cultivation of single cells was implicit in the 

 fundamentals of the "cell theory" but was neither 

 clearly expressed as a distinct concept nor sub- 

 jected to experimental test during this period. 

 1900-1922 — The idea of tissue cultures was out- 

 lined for the first time in its broad aspects by 

 Haberlandt in 1902 and was first put into practice, 

 with animal tissues, by Harrison in 1907 and by 

 Burrows and Carrel in 1910. Efforts aimed at 

 the establishment of similar cultures of plant tis- 

 sues were fruitless until 1922 when Kotte and Rob- 



