EFFECT OF CROWNGALL INOCULATIONS ON 
BRYOPHYLLUM 
By Erwin F. Smith 
Pathologist in Charge , Laboratory of Plant Pathology , Bureau of Plant Industry, United 
States Department of Agriculture 
In November, 1919, Michael Levine published a paper 1 in which 
he called in question some of my recent work on crowngall, 2 maintaining 
as the result of his own experiments: (1) That the shoots found in leafy 
crowngalls originate from the tumor tissue rather than from groups of 
normal totipotent cells disrupted and set growing by the growth of the 
tumor as I have maintained; and (2) that if my theory of embryomas is 
correct any totipotent tissue should be set growing—for example, dor¬ 
mant buds—yet in Bryophyllum calycinum Salisb. the crowngall organism 
(Bacterium iumejaciens Sm. and T.) has no stimulating effect on the forma¬ 
tion of shoots , but rather an inhibiting effect. 
I had never tried Bryophyllum calycinum for crowngall inoculation until 
after the appearance of Mr. Levine’s paper; then it seemed worth while 
to make some experiments with it. From statements in his paper I 
thought the plant might react differently from tobaccoes, geraniums, 
and other plants which had given me numerous crowngalls containing 
abortive roots or shoots, but I have not found it to do so. In fact, 
working on the same plant and using the same microorganism (the one I 
originally sent to his colleague, Dr. Isaac Levin) I have obtained results 
quite like those obtained on other plants, as may be seen from the illus¬ 
trations accompanying this paper. 
In passing, it may be said that removal of leaves from the parent plant 
before inoculation is not good technic because they would then have 
1 Levine. Michael, studies on plant cancers, i. the mechanism op the formation op the leafy 
crown gall. In Bui. Torrey Bot. Club, v. 46, no. 11, p. 447-452, pi. 17-18. 1919. Abstract in Exp. Sta. 
Rcc., v. 43, no. 3, p. 242. 1920. The summary and conclusions of Mr. Levine’s paper are as follows: 
" 1. Bacterium tumefaciens inoculated by prides of a delicate needle into the marginal notches of a leaf 
°f Bryophyllum calycinum, where totipotent cells are present, results in the formation of a crowngall as 
readily s in other plants used for inoculation but without leafy shoots. 
“ 2. Inoculation of Bacterium tumefaciens into the tissue of a leaf of B. calycinum in the vicinity of a small 
bud causes the formation of a gall and interferes with the normal development of the bud or leafy shoot. 
** 3. Inoculation of Bacterium tumefaciens into the midvein of a young or old leaf detadied f rom or attached 
to the mother plant results in the development of a large gall without the development of leafy shoots. 
“4. Inoculation of Bacterium tumefaciens into the growing region of the stem of a young plant causes the 
development of the ordinary crowngall with the occasional and subsequent development of a leafy shoot. 
“5. Bacterium tumefaciens does not cause the formation of leafy shoots in Bryophyllum calycinum but 
rather inhibits and retards their normal development, when inoculated into the totipotent cells which 
appear at the notches of the leaf.” 
3 Smith, Erwin F. crowngall studies showing changes in plant structures due to a changed 
stimulus. Preliminary paper. In Jour. Agr. Research, v. 6, no. 4, p. 179-182, pi. 18-23. 1916. 
- Embryomas in plants (produced by bacterial inoculations). In Bui. Johns Hopkins 
Hosp., v. 28, no. 319, p. 277-294, 1 fig., pi. 26-53 on 14. 1917. 
Journal of Agriculture Research, 
Washington, U. C. 
yq 
Vol. XXI, No. 8 
July 15, 1921 
Key No. G 238 
(593) 
