II.— BOTANY. 



Akt. XXXI. — On Heterostyled Trimorphic Flowers in the 

 New Zealand Fuchsias, with Notes on the Distinctive 

 Characters of the Species. 



By T. Kikk, F.L.S. 



[Read before the Wellington Philosophical Society, 18th January, 1S93.~] 



Plate XIX. 



Exactly a century ago it was observed by Sprengel that the 

 European water-violet (Hottonia palustris, Linn.) produced 

 flowers of different forms on different plants ; in one form the 

 pistil was more than twice the length of the pistil of the other. 

 Although convinced that the phenomenon was not accidental, 

 he was unable to discover any reason for its occurrence, and 

 nearly seventy years elapsed before light was thrown on the 

 subject. It is now well known to be a contrivance to insure 

 fertilisation by means of pollen obtained from flowers of 

 another plant, and it has been proved by experiment that the 

 number of perfect seeds in each capsule tbus fertilised is 

 much greater than when pollen is applied from the same 

 plant, or from the same form of flower. Pollen from the 

 anthers of either form of flower must be applied to the stigma 

 of the other in order to obtain the most advantageous 

 results. 



Flowers of this kind are said to be " heterostyled " : but, 

 inasmuch as the difference in the length of the style is often 

 correlated with differences in the length of the stamens, the 

 size of the pollen-grains, and the size of the flower, &c, the 

 late Professor Asa Gray suggested that the term was not 

 sufficiently expressive, and proposed to substitute "hetero- 

 gone" or " heterogenous "; but, notwithstanding the greater 

 comprehensiveness of the latter term, it has not been generally 

 adopted. 



Mere difference in the length of the style or stamens, or 

 both, is not of itself sufficient to render a plant heterostyled ; 

 there must be a reciprocal relationship between the pollen of 

 one form of flower and the stigma of the other : this may or 

 may not be accompanied by a difference in the pollen and 



