BIOCHEMICAL STUDIES OF HYBRIDS 



323 



28 



i > 



20 > 

 to* 



16 4* 

 12 

 8 H 



47 -o 



11 



M-1- 



8°. 



M-2h 



Leucantha 



-j I I ^>&^^&'T^4 ^ Viridis 



4 



Leucophaea 



o o 

 o o 

 o o 



00 O 03 



o « o o 



o 



O 

 00 



o 

 o 



Fig. 15-4. A three-way plot of individual hybrid types and pure 

 species. Open circles indicate plants from tri-hybrid population, 

 closed triangles indicate miscellaneous supplementary plants from 

 pure populations, and closed circles indicate the additional (sup- 

 plementary) Baptisia leucantha X B. sphaerocarpa hybrids. Points 

 along the X-axis represent the number of compounds recognized of 

 B. sphaerocarpa; points along the Y-axis represent (above) the 

 number of compounds recognized of B. leucantha and (below) the 

 number of compounds recognized of B. leucophaea. Hybrids fall 

 at some angle between the X and Y axes. 



If a large population of B. leucantha x B. sphaerocarpa is 

 analyzed by these methods the Fi's will be indicated by- a primary 

 cluster of points, backcrosses will be indicated by secondary and more 

 diffuse clusters. The morphological discontinuity between the hybrids 

 and pure species plus the small proportion (5 per cent) of total hybrids 



