252 Dr. Ida A. Keller on the 



plants, where the male and female organs are borne on distinct 

 flowers but on the same plant. 



II. A specially adapted or conspicuous corolla. — It is these 

 showy, irregular, or peculiarly shaped corollas that insects 

 may readily be observed to visit. The questions which here 

 arise are numerous. The first one to present itself is this : 

 Has the corolla been developed for the purpose of attracting 

 insects, and is it the proof which nature gives us that cross- 

 fertilization is a necessity, or that it is at least favourable to 

 the preservation of the species ? This seems to have been 

 definitely answered in the affirmative. The number of cases 

 where the insect has actually been seen to transport the pollen 

 from one plant to another, however, are few compared with 

 the great number of species whose flowers would come under 

 this head. In this connexion it must be remembered how 

 very often the insect is simply a robber. This past summer 

 I observed, e. g., a very large patch of Oerardia pedicularia, 

 the flowers almost all being pierced at the base of the corolla 

 by bees perching on the outside and never touching stamens 

 or pistil. Now, wherever it is more convenient for the insect 

 to reach the desired substance without boring a hole, it is 

 apt to be taken for a benefactor, even if it simply takes from 

 the flower without rendering any service in return. There is 

 another suggestion I would offer in regard to insect visitors. 

 In observing bees travelling to and from flowers of Kahnia 

 latifoh'a, I noticed that very frequently pollen is thrown upon 

 the pistil of the same flower when the stamens are unfastened 

 by the insect. I am not prepared to assert, however, that 

 such flowers proved fertile. I simply throw this out as a 

 suggestion, and it should be taken for what it is worth. 

 Professor "Willis made somewhat similar observations on the 

 flowers of Phacelia tunacetrfolia. He describes the crawling 

 of insects over the dense cymes, touching stamens and styles 

 indiscriminately, and probably knocking the pollen on the 

 stigmas from the surrounding anthers *. Further, he says 

 in regard to 1'hacelia campanularia : — " Bees alight some- 

 times on the corolla, touching styles and stamens, crushing 

 them all up together with the styles, and probably causing 

 self- as much as cross-fertilization " "j". This in spite of the 

 fact that the flower of this plant is to all appearance well 

 adapted to secure cross-fertilization. I should not be surprised 

 if, sooner or later, upon close examination it should be found 



* " Contributions to the Natural History of the Flower/' Journ. Linn. 

 Soc. Loud., Botany, vol. xxx. p. 55. 

 j Ibid. p. 57. 



