TETRAPLOIDS 



115 



sented in the middle to the right and those of the parent 

 type to the left. 



A tetraploid tomato plant, also, Avas obtained as follows. 

 A piece of a young tomato plant was grafted on to a stock 

 of nightshade in the usual way (Fig. 67). After union 



NoPTDaHn) Gi|as(g: 



Nopmalln) Gi^as(§) 



r 



n 



Fig. 69. 

 Diploid and tetraploid seedlings and flowers of the nightshade are 

 shown above, and tissue cells below. Above to left, seedlings; 

 above to right, flowers; below to left, palisade cells; in middle, 

 pollen grains; to right stomata, above, and hairs below. (After 

 Winkler.) 



had been perfected, a cut was made across the union of 

 the two plants and the axial buds removed from the stock. 

 From the cut surface, young buds developed in the callus 

 tissue. These were removed and planted. One of these 

 had an epidermis of nightshade cells and a core of tomato 

 cells. It was found on further examination that the epi- 

 dermal cells were diploid and the cells of the core were 



