Introduction 7 



produced leaves or roots depended on that cell's 

 fortuitous position, whether distal to or proximal 

 to the nearest cut surface or uninjured growing 

 point. If a three-foot piece of willow was left 

 intact, the distal foot of stem would produce only 

 roots, but if a six-inch piece was isolated from the 

 distal end of such a stem either by removal or 

 merely by severing the bark, the proximal three 

 inches of this piece would produce leaves instead 

 of roots. Later observations by von Goebel ( 1908, 

 293) (Fig. 1) Schwanitz (1935, 323) and others led 

 to similar conclusions. Here the morphogenetic 

 pattern was a function of the "organism as a 

 whole" (considering here the autonomous frag- 

 ment as the organism), of the relationships of cell 

 to cell within the particular tissue continuum. 

 The cell appeared to be totipotent, its actual ex- 

 pressed function being a resultant of the in- 

 fluences coming from outside. Vochting's second 

 approach involved the age-old method of grafting 

 (Fig. 2) or transplantation (1892, 330, 1894, 331) 

 and merely confirmed what had been known from 

 time immemorial, that no matter what the environ- 

 ment or host into which a scion was transplanted, 

 it always developed in a given pattern which was 

 fixed by the species from which it came. Not only 

 was the developmental pattern fixed, but the 

 physiological behavior was also fixed by the spe- 



