HERMAPHRODITISM. 75 



stamens to reach the stigmas of the flower, or even to be dusted 

 upon them by the unconscious agency of the intruding insects. 

 Moreover, as among animals, so among plants, it is common 

 for the male organs to become mature before the carpels are 

 ready, or, in rarer cases, for the reverse to occur. 



There is no doubt that cross fertilisation very generally 

 occurs, and it is physiologically probable that this is a con- 

 siderable advantage, though less among plants (which are so 

 very "female," i.e.^ vegetative) than among animals. But there 

 is an increasing impression that both the occurrence of cross- 

 fertilisation, and the necessity of it among higher plants, have 

 been exaggerated by the extreme Darwinian school. One of 

 the most thoughtful and observant of American botanists, Mr 

 T. Meehan, has raised a vigorous protest against the prevalent 

 view. In the Yucca^ or Adam's needle, which is regarded as 

 cross-fertilised by insects, he showed by experiment that there 

 was in each flower " no abhorrence of its own pollen." " Even 

 when fertilised at all by insects, I am sure the fertilisation is 

 from the pollen of the same flower." 



Then as to mechanical contrivances, he says, " we are told 

 that iris, campanula, dandelion, ox-eye daisy, the garden pea, 

 lobelia, clover, and many others, are so arranged that they 

 cannot fertilise themselves without insect aid. I have enclosed 

 flowers of all these named in fine gauze bags, and they produced 

 seeds just as well as those exposed." 



We cannot here enter into a full statement of Meehan's 

 careful observations, but his three main propositions well 

 deserve statement and due consideration : — 



1. Cross-fertilisation by insect agency does not exist nearly 

 to the extent claimed for it. 



2. Where it does exist, there is no evidence that it is of any 

 material benefit to the race, but to the contrary. 



3. Difficulties in self-fertilisation result from physiological 

 disturbances, that have no relation to the general welfare of 

 plants as species. 



§ 8. Comple?iiental Males. — When Mr Darwin was inves- 

 tigating barnacles and acorn shells, in preparation for his 

 monograph on the group, he discovered the remarkable fact 

 that some of the hermaphrodite individuals carried minute 

 males concealed under their shells. These he regarded as 

 advantageous accessory forms, ensuring cross-fertilisation in the 

 hermaphrodites which harbour them. The great majority of 



