=193. Transfer.= After the species to be used for experiment has been chosen, the various habitats or areas selected, and the direct factors measured by instruments, the actual transfer of the individuals is made by means of seeds, preferably in autumn, though the results are practically the same if seeds are kept over the winter and planted at the opening of spring. The natural method is to scatter the seeds in the place selected, as though they had been carried by the usual agents of migration. The mortality is usually great in such case, however, and the chances of success are increased by actually planting the seeds. This is the method which has been used in making cultures of species of the European Alps on the summit of Mount Garfield in the Rocky mountains. The number of seeds used is recorded in order to obtain some estimate of germination and competition. While the use of the seed or disseminule possesses the great advantage of making the experiment essentially a natural one, the transfer of rosettes, seedlings, or young plants makes the results more certain, and consequently saves time, even though the actual transfer is somewhat more difficult. It is hardly necessary to point out that the removal of the plant should be made with the greatest care. The best success is obtained by making the transfer on cloudy or rainy days, and when shade plants are to be placed in sunny situations, they should be transplanted late in the afternoon. When the task of carrying them is not too great, it is a distinct advantage to move a number of individuals in the same block of earth. The transfer of mature plants is inadvisable, except for those perennials which can not readily be secured in an early stage. This naturally does not apply to woody plants, evergreen herbs, mosses and lichens; the last two may be transferred at any time with satisfactory results. Each culture is carefully marked with stakes, and definitely located by means of landmarks. [Illustration: Fig. 46. Series for producing hydrophytic forms under control: 1, amphibious; 2, floating; 3, competition; 4, submerged.]