1915] The Ottawa Naturalist. 147 



Although much more conspicuous and pretentious in 

 aspect the ordinary showy petaliferous flowers of our violets 

 are of far less importance for the propagation of the individuals 

 than are the cleistogamous ones. This is evident from the fact 

 that only in few cases do they produce any seed. Their life 

 generally ends with the withering of their petals, shortly after 

 which all traces of the whole flower are gone. In most cases, 

 there is no postfloral maturing of capsules because the ovules 

 are incapable of developing into germinable seeds. The reason 

 for this sterility is simply that, as a rule, the petaliferous flowers are 

 not fertilized. They lack the abilit}^ of self-fertilization and are 

 consequently dependent for their fertilization on outer agencies. 

 Furthermore, special arrangements and morphological peculiar- 

 ities of the sexual organs, the nature of which need not be describ- 

 ed in this connection, tend to make self-fertilization extremely 

 difficult, if not wholly impossible. 



Under these circumstances it is evident that when seed is 

 found developed in the capsule of a petaliferous violet flower, 

 it must be regarded as the result of a cross-fertilization between 

 two flowers. These two flowers may belong to- the same in- 

 dividual, to two difl^erent individuals of the same species or 

 to two individuals of distinct species. To which one of these 

 three possibilities the development of seed in the capsules of 

 petaliferous flowers is to be attributed in individual cases 

 can only be determined by a study of the progeny raised from 

 this seed. 



That the capsules of petaliferous flowers in most species of 

 our violets frequently produce germinable seed, is beyond doubt. 

 Actual observation supporting this statement are, however, 

 rather scant. Brainerd^ states that though the infertility of the 

 petaliferous flowers has often been observed, he has "during 

 the past season (1903) found these capsules to be usually fertile." 

 In the vicinity of Ottawa the same observations have been made 

 on V. Macounii Greene and the writers believe they could be 

 easily made on practically all species of acaulescent violets 

 were these more closely observed. 



That fertilization of petaliferous flowers really often takes 

 place, is demonstrated beyond a doubt, by the frequent occur- 

 rence of hybrids between different species of violets. As the 

 formation of hybrids through cross-fertilization of the cleist- 

 ogamous flowers is wholly out of the question the mere fact 

 of their occurrence must necessarilv prove that fertilization 

 of and seed formation from petaliferous flowers often occur. 



Rhodora, Vol. 6., p. 10. 



