E. R. Saunders 



161 



stem, or pod, regarded as an isolated structure apart from its position 

 in the life-cycle, can be relied upon to reveal the constitution of the 

 intermediate individual. This may be equally true for the whole plant 

 unless it is taken at some critical stage. The regular sequence in de- 

 velopment and the irregular effects of what seem to be fluctuations in 

 physiological equilibrium (due to whatever cause) must be taken into 



Hoary 



Fully hoary 



Var. 



Partially hoary 



r- 



Sub-glabrous 



Type ir 



semt-tncana 



Glabrous 



Mid-hoary (crossbred) 



Quarter-hoary (crossbred) 



(Crossbred) («)/ \ (c) Homo- or heterozygous 



^h^^^*^ ^*y \ id) Homo- or heterozygous 



zygous 



iWholly glabrous 



account. Except in the extreme grades at either end of the scale it is 

 the range which defines the class, and with an overlapping range through- 

 out the series repeated observations are required as development proceeds. 

 In the scheme given on p. 162 the range of variation for each plant 

 member in each grade is set out so that the combination serving to 

 distinguish each form is appreciable at a glance. For convenience of 

 reference the factorial constitution established as the outcome of the 

 crossbreeding work is also included. 



