OENOTHERA MUTANTS WITH DIMINUTIVE CHROMOSOMES 509 
less the ruhrinervis in which Gates found 14 chromosomes dupHcated 
this type instead of de Vries's mutant), the type is not a new one, 
having been figured by MacDougal as early as 1905. 
Fig. 4. 0. ruhrinervis {'^), plant Xo, 3903, C. S. H., 1908. Flower photographed 
in early morning, showing "crimped" petals. 
C. 14+1-CHROMOSOME Mutants 
I. Recent discoveries indicative of the production of '/^^-chromosome 
gametes hy 14- and -chromosome forms 
The discovery of chromosome degeneration in 14 + -chromosome 
forms by Geerts Cii), together with later studies of this peculiar 
irregularity in 15-chromosome forms by Gates and Miss Thomas ('14), 
