170 PROCEEDINGS OF THE ACADEMY OF [1897. 



the sun has reached the summer solstice. When the sun ceases to 

 woo it, the flower opens, only to find its beloved going away. Less 

 than three months of flowering will, therefore, have been occupied 

 in this enormous seed production. 



The facts here detailed have an important bearing on two points 

 maintained by me, in connection with the life-history of plants: — 



I have recorded numerous observations in the Proceedings of the 

 Academy, commencing with 1866, showing that the growth-energy 

 of plants is rhythmic, dependent on the power of the plant, or the 

 parts thereof, to convert nutrition into the growth-force, and that 

 the various forms which plants present are the result of varying 

 phases of life-energy, in most cases of no physiological value, and 

 with which environment has little to do. The evidence furnished 

 by Heliophytum, though of a negative character, is surely strong. 

 Through the long ages the plant has been established over a vast 

 area, and consequently subjected to many varying and varied con- 

 ditions of environment ; it has continued as a compact genus or sec- 

 tion distinct from Heliotropium, without any material change that 

 would warrant a modern botanist in making new species of it. 



Again it has been maintained by me that as environment can 

 have no important influence on changes of form, the free and un- 

 trammelled production of seed would be of far more importance 

 in a supposed "struggle for life" than any power of adaptation 

 could be that depended more on an occasional cross for its increased 

 energy. Dean Swift's satire in which the Lilliputians, by the mere 

 force of numbers, are made to overcome the giant Brobdingnagians, 

 cannot be supported in every case by the histories of plants, but 

 when it comes to a question of distribution, numbers surely are the 

 more likely to hold the field. 



I think I may claim the credit of advancing the further proposi- 

 tion that a free production of seed may always be taken as an a 

 priori indication of self-fertilization. In cleistogamic flowers the 

 certainty of seed-bearing is well known. With rare exceptions the 

 huge natural order of Composite are self-fertilizers, and they have 

 managed to embrace within themselves about one-tenth of the whole 

 vegetable kingdom. Where the wind or an insect is the agent in 

 fertilization, the agent does not always come along. On plants de- 

 pendent on this outside assistance, numerous flowers fail to seed. 

 No plant so dependent ever perfects all its seeds ; in many cases 

 utter failure follows. In this remarkable plant there is no indica- 



