distribution of roots on the tubers, smoothness of the tuber skin, 

 shape of the tubers, and so forth. Most of these characters can best 

 be judged from clones derived from individual seedlings. 



Some data on inheritance have been produced (7). In Guade- 

 loupe, crossing the long-stoloned 'Cousse-Couche Violette' (stolons 

 10 to 15 centimeters) with the short-stoloned *INRA 40' (stolons 

 less than 10 centimeters) produced the following distribution of 

 mean stolon length among the progeny: 



Stolon length (cm) Percentage of seedlings 

 Less than 10 32.2 

 10-15 26.2 

 15-20 20.8 

 More than 20 20.8 



In the same cross, the following tuber forms were found among 

 the seedlings: 



Shape Percentage of seedlings 



Spheroid (as in 'INRA 40') 17.3 



Ovoid 20.2 



Cylindrical 6.5 



Club shaped (as in 32.3 

 'Cousse-Couche Violette'). 



Club shaped, branched 17.9 



Fan shaped 5.8 



The outer phelloderm color and flesh color segregated as follows: 



^. . . Skin colors (percent) 



Flesh colors 



Deep purple Purple Light purple White Total 



Deep purple 3.3 1.6 ... ... 4.9 



Purple 22.9 ^18.0 ... 40.9 



Light purple ... 3.3 18.0 . . . 21.3 



Very light purple 1.6 3.3 ... 4.9 



White 1.6 6.6 2i9.6 27.8 



Total 3.3 31.0 45.9 19.6 



1 'Cousse-Couche Violette'. 



2 'INRA 40'. 



These data suggest complex inheritance based on a large number 

 of segregating genes. 



VARIETIES 



Named varieties of D, trifida are not uncommon, but the ma- 

 jority have not been described. Henry (18) described 43 accessions 

 from Trinidad, 3 from Guyana, and 1 from Jamaica. As variety- 

 distinguishing characters, he emphasized leaf lobe number, the 

 overlapping of basal leaf lobes, length of the central lobe, stem 

 width, shapes of the immature and mature tubers, and the com- 

 pactness of the cluster. On this basis, Henry was able to show that 



12 



