FURTUHR RliSl'.AR(.Hi:S IN DlSHASES OF Pl.ANTS 525 



at some fundamental knowledge of what was tlien described as 

 the '* pre-canccrous stas^e "' ' in plant and animal malignancies. 

 The "chemical and physical stimuli underlying tumor-formation " 

 was liis basic theme and the subject was extended to include " the 

 production of teratosis in the absence of tumors and of parasites." " 



Proliferation experiments with the cultivated plant, Begonia 

 phylioffhiniacj, supplied material for many of his conclusions. 

 It, because of its watery nature and especially sensitive and very 

 permeable cell-membranes, was suited to studies of temporary 

 loss of function by chilling, heat, anesthetics, acids, or excessive 

 loss of water supply due to woundings or other causes. His paper 

 on " The Cause of Proliferation in Begonia Phyllomaniaca " ° had 

 been read on November 18, 1918, before the National Academy 

 of Sciences, and, in it, among other important points, he attached 

 special significance to his discovery that proliferation may occur 

 in young tissues at a long distance from the point of wounding. 

 In fact, the wounding might be in the root, and astonishing 

 proliferation take place in the young tissue at the top of the plant. 

 He accounted for this on the basis of shock induced by the 

 " sudden interruption of the water current," causing " cell-pre- 

 cipitates or plasmolysis of the young totipotent cells which begin 

 to grow when they have recovered from the shock." These adven- 

 tive shoots are not branches, he said, " since they have no initial 

 connection with the ordinary cambium, or xylem-phoem of the 

 mother plant. They are rather to be classed with filial teratomas. 

 Later, a small proportion of them establish connections with the 

 conductive tissue of the mother and persist, i. e., become abnor- 

 mally situated branches." 



His paper, " Embryomas in Plants," ' the original basis of 

 which was his address in 1916 before the Johns Hopkins Medical 

 Society, had had to do mainly with tumors in plants, produced 

 by bacterial inoculations. When writing of growths from cut 

 surfaces in tobacco, how^ever, he had pointed to a tendency 

 " always there " toward adventive buds or shoots " if the stimulus 

 is strong enough," and this was so " not only in tobacco but 



* Intro, to bad. dis. of plants, op. cit., 571. Also, pp. 483, 511. 

 ^ Idem, part. IV, 3rd, 4th, and 5th subsections, pp. 477-632. 

 "Proc. Nafl Acad. Sci. 5: 36-37, Feb. 1919. 

 "•Johns Hopkins Hasp. Bull. 28(319): 277-294, Sept. 1917. 



