in Hybridisation 347 



EXPERIMENTS WITH HYBRIDS OF OTHER SPECIES OF PLANTS. 



It must be the object of further experiments to ascertain 

 whether the law of development discovered for Pisum 

 applies also to the hybrids of other plants. To this end 

 several experiments were recently commenced. Two minor 

 experiments with species of Phaseolus have been completed, 

 and may be here mentioned. 



An experiment with Phaseolus vulgaris and Phaseolus 

 names gave results in perfect agreement. Ph. nanus had 

 together with the dwarf axis, simply inflated, green pods. 

 Ph. vulgaris had, on the other hand, an axis 10 feet to 

 12 feet high, and yellow-coloured pods, constricted when 

 ripe. The ratios of the numbers in which the different 

 forms appeared in the separate generations were the same 

 as with Pisum. Also the development of the constant 

 combinations resulted according to the law of simple com- 

 bination of characters, exactly as in the case of Pisum. 

 There were obtained 



Constant Axis Colour of Form of 



combinations the unripe pods the ripe pods 



1 long green inflated 



2 constricted 



yellow inflated 



constricted 



5 short green inflated 



constricted 

 yellow inflated 



constricted 



The green colour of the pod, the inflated forms, and the 

 long axis were, as in Pisum, dominant characters. 



Another experiment with two very different species of 

 Phaseolus had only a partial result. Phaseolus nanus, L., 

 served as seed parent, a perfectly constant species, with 

 white flowers in short racemes and small white seeds in 

 straight, inflated, smooth pods ; as pollen parent was used 

 Ph. multiflorus, W., with tall winding stem, purple-red 

 flowers in very long racemes, rough, sickle-shaped crooked 

 pods, and large seeds which bore black flecks and splashes 

 on a peach-blood-red ground. 



