Presumptive Mutations in Wild & Cultivated Plants 65 



the same wild mutation elsewhere. The flowers have five spurs 

 and this type is now known as peloria nectaria. There is another 

 type, peloria anectaria, in which the flowers are actinomorphic, but 

 without spurs. Another race studied by de Vries, which he called 

 hemipcloria, produces usually a single (terminal) peloric flower on 

 each plant. Such a flower may not appear in some years, or 

 occasionally more than one may appear, and this seems to be 

 controlled to some extent by the environment, but the capacity for 

 producing a peloric flower is evidently inherited through the 

 seed. In breeding from such a half-race de Vries finally obtained 

 mutations to the full peloric condition, in the fifth and sixth 

 generations of culture. This mutation occurred with a frequency 

 of about 1%, and although highly sterile it probably breeds true. 

 Whether there are any plants which never produce a peloric flower 

 is uncertain. 



A similar peloric condition (Digitalis purpurea monstrosa) has 

 long been known in foxgloves, in which a single, erect terminal 

 peloric flower occurs on the plant, and opens before the other 

 flowers, which then follow in acropetal succession. The peloric 

 flower frequently also shows an increase in the number of parts. 

 This condition is found by Keeble, Pellew and Jones (1910) to be 

 inherited as a simple Mendelian recessive. The peloric flowers are 

 perfectly fertile with their own pollen, the inheritance being the 

 same through peloric or normal flowers of the plant. 



In Antirrhinum majus, as in many other plants with 

 zygomorphic flowers, sporadic peloric flowers occasionally occur. 

 There is also a completely peloric race, which Baur (1911) used in 

 his extensive crosses. He concluded that zygomorphy depended 

 upon the presence of two factors P and E. In the absence of E 

 the plant will have only peloric flowers, but plants having E without 

 P (EEpp) produce both peloric and normal flowers. This is an 

 interesting case of somatic segregation in the presence of one pair 

 of factors, and presumably there would be no difference in 

 inheritance from the two types of flower on the same plant. If 

 such an EEpp individual is crossed with a fully peloric race 

 (eePP), the P^ (EePp) bears only normal flowers, while the F a gives 

 (1) normal-flowered plants, (2) plants with both normal and peloric 

 flowers, (3) plants with only peloric flowers, in the ratio 9:3:4. 

 The numbers actually obtained were 70 : 13 : 45, and the departure 

 from expectation (72 : 24 : 32) is explained by the fact that badly 

 nourished plants belonging to class (2) produce only peloric flowers, 



