558 PROCEEDINGS OF THE ACADEMY OF [1895. 



the intention is clearly shown. We cannot, however, speak with 

 certainty of cross-fertilization even in all these cases, except in wholly 

 dioecious plants, at least not in Darwin's understanding of the terra, 

 which is, that "cross-fertilization always means a cross hetween dis- 

 tinct plants raised from seeds." We must, therefore, he careful not 

 to include too hastily in this category monoecious plants, where the male 

 and female organs are home 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 

 favorable 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 connection 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 Gerardia 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 Kalmia latifolia 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 tanacetifolia. 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. 2 Further, he says in regard to Phacelia Campanula via: 



2 Contributions to the Natural History of the Flower, Jour. Linnaeu Society, 

 London, Botany, Vol. XXX, p. 55. 



