TETRAPLOIDS 



113 



at the graft level (Fig. 67). Adventitious buds grew up 

 from the callus tissue of the exposed surface. One of 

 these plants was a chimaera, i.e., a plant part of whose 

 tissue was nightshade and part tomato. It was removed 

 and propagated. Some of the axial buds of the new plant 



Fig. 67. 



a, Seedling of Solanum nigrum, b, Seedling of Solanum lycopersicum. 

 c, Solanum tubingense — graft-hybrid, d, method of grafting. (After 

 Winkler.) 



had a tomato epidermis and a nightshade core. These 

 branches were then isolated and planted. The plantlets 

 differed from other chimaeras known to be diploid, which 

 created a suspicion that the new type might have a tetra- 

 ploid core, which was confirmed by examination. The tops 

 of these chimaeras were cut off, and the axial buds of the 

 basal half removed. From the adventitious buds of the 



