116 THE THEORY OF THE GENE 



tetraploid. In order to obtain, from this composite plant, 

 a tetraploid in all of its parts, the stem of a young plant 

 was cut across and the axial buds below the cut were 

 removed. New adventitious buds appeared on the cut 

 surface which were, for the most part, made up of the 



Giant Haploid 24 Giant Diploid 48 



c d 



Fig. 70. 

 a, Haploid ; 6, diploid cell and chromosomes of nightshade ; c, hap- 

 loid, and d, diploid cell and chromosomes of tetraploid night- 

 shade. (After Winkler.) 



tomato tissues both within and without. The giant tomato 

 plant differs from the parent plant in the same way as 

 does the giant nightshade from its parent. 



The diploid nightshade has 24 chromosomes, its hap- 

 loid number is 12; the tetraploid has 48 chromosomes, 

 and its haploid number is 24 chromosomes. The diploid 

 tomato has 72 chromosomes (haploid 36). The tetraploid 



