1915] The Ottawa Naturalist. 149 



The conspicuous vegetative development of certain wild 

 violet forms, the systematic value of which may at first seem diffi- 

 cult to understand, may therefore often indicate, to the student 

 of violets, their hybrid value. It must be understood, though, that 

 however helpful be the general characteristics briefly hinted 

 at above for the recognition of hybrids, the decision as to whether 

 a suspected form be really a hybrid or not can be satisfactorily 

 reached only through a minute study of its morphological and 

 sexual characteristics. This means not only that a violet in 

 order to be classified as a hybrid, should be intermediate between 

 supposed species as far as vegetative characters are concerned, 

 but also, and particularly, that the morphological and cyto- 

 logical development of its sexual organs should most strongly 

 support its supposed hybrid nature. In doubtful cases, the 

 functional capacity of the pollen and the ovula must really 

 furnish the final decision on the question whether a certain indivi- 

 dual should be regarded as a hybrid or not. Space will not permit 

 that in this article European literature bearing upon the subject 

 of hybridization as influencing the development of sexual organs 

 in violets be quoted. This is also, in fact, unnecessary as num- 

 erous observations relating to the subject have been recorded 

 in North America. This is especially true as far as the develop- 

 ment of seeds in hybrid violets are concerned, in other words, 

 as far as the development of, or rather the failure of develop- 

 ment of the female organs is concerned. 



Strangely, but as a matter of fact most naturally, con- 

 trasting with the luxuriant growth of the vegetative organs 

 of a violet hybrid stands its more or less marked sexual impotence, 

 i.e. , its incapability, to a greater or less degree, of reproducing itself 

 sexually. Generally a violet hybrid is markedly barren and al- 

 though developing numerous capsules and ovules fails to pro- 

 duce an adequate number of germinable seeds. 



A few quotations from one of the excellent papers of Dr. 

 E. Brainerd' on the subject will suffice. Thus, describing the 

 hybrid plants between V. septentrionalis and V. fimbriatula 

 Dr. Brainerd says that "in the late summer they produce 

 numerous cleistogamous flowers and fruit, but nine-tenths of 

 the ovules remain unfertilized."* Observations on hybrid 

 plants of the combination V. cucullata x fimbriatula also reveal 

 the fact that specimens of the same in their cleistogamous 

 flowers, develop capsules which either contain only a few rip- 

 ened seeds or even become "brown and withered as though 



3 Rhodora, Vol. 6. pp. 213-223. 

 * I.e. 216. 



