PLATE XIX 



Teratoid crowngalls produced in castor-oil plant (Ricinus communis) by inoculating 

 Bacterium, tumefaciens (hop strain), the inoculations being made in the upper leaf 

 axils of young, vigorous, unbranched plants. 



Fig. A. — A red-stem variety. Leaves refiexed; axis distorted; and feeble shoots 

 developing out of the axillary tumors. There are on the tumors other smaller shoots 

 not shown here distinctly. Time, 13 days. 



Fig. B. — A green-stem glaucous variety. As in figure A, but time 17 days. Here 

 also internal growths (root anlage) are pushing up the tissues of the stem below the 

 lower leaf. A few days later these roots appeared on the surface, both of this intemode 

 and of the one above it. This phenomenon has been recorded previously by the 

 writer as sometimes occtu^ring on inoculated stems of the Paris daisy and other plants 

 in the vicinity of developing tumors (Smith, E. F. Bacteria in Relation to Plant 

 Diseases, vol. 2, fig. 26. 1911). 



