530 Boodle. — The Trifoliolate and other Leaves of Gorse. 
soil. This is the reverse of the result with gorse, but, as the wild form of 
the wallflower is more or less xerophytic (growing on rocks, sea-cliffs, &c.), 
this again appears to be a case of an ancestral character being favoured by 
ancestral soil conditions. 
More general theoretical considerations are not included in the present 
note, as the writer hopes to carry out further experiments, which should 
yield a better basis for the discussion of the subject. 
Jodrell Laboratory, Kew, 
