Page:An introduction to physiological and systematical botany (1st edition).djvu/343

 Rh experiments upon which Linnæus founded his opinion, as well as the objections it has had to encounter. It would be endless, and altogether superfluous, to bring forward new facts in its support, nor shall I do so, except where new arguments may render such a measure necessary.

The Stamens and Pistils of flowers have, from the most remote antiquity, been considered as of great importance in perfecting the fruit. The Date Palm, from time immemorial a primary object of cultivation in the more temperate climates of the globe, bears barren and fertile flowers on separate trees. The ancient Greeks soon discovered that in order to have abundant and well-flavoured fruit, it was expedient to plant both trees near together, or to bring the barren blossoms to those which were to bear fruit; and in this chiefly consisted the culture of that valuable plant. Tournefort tells us that without such assistance dates have no kernel, and are not good food. The same has long been practised, and is continued to this very day in the Levant, upon the Pistacia, and the Fig.