While it is probably true that vegetation originated simultaneously at different points on the globe’s surface, not much observation is necessary to indicate that it does not always stay where it is put. Plants are peculiar and native to certain lands in a very definite way, but their love of adventure often carries them to the far corners of the earth. They are the most energetic and effective colonizers in existence. The complete history of plantdom would include the stories of invasions, conquests and revolutions quite as stirring as anything in human annals. If it is absorbing to follow the racial movements of man, ancient and modern, it is equally fascinating for a lover of plants to investigate _their_ migratory habits. We have exact records of many of their travels and can make interesting conjectures about the rest. To a layman, the present distribution of plants may seem chaotic. He reads that certain families are natives of Europe and Australia, or North America and Africa and are absent from all intervening countries. The Alpine species _Primulas_ and _Saxifrages_ are common to both the Arctic and the Antarctic. There are fifty-eight European and New Zealand species which are identical. The British Grass _Poa Annua_ is also found in the Andes of Brazil. Through what thousands of years of change and evolution have these things come about! Yet the results are no more complex than was the filling of America with its mixed and conglomerate human population. In a general way, there is a measure of fixity to plant distribution. Certain plants have elected the tropics as their home; and only under the greatest stress of circumstance can they be induced to go elsewhere. Tropical heat and moisture make for luxuriance of vegetation. There is a much greater variety there than in the North. Woody Vines climb the tallest trunks, where they intermingle their leaves and blossoms with those of their host. Gorgeous Air Plants beautify and perfume the forest. Stately Palms wave magnificent bouquets of pendulous fronds. As we travel away from the equator, the vegetation takes on a simpler aspect. There are more annuals and more herbs. The number of Ferns, Grasses, and catkin-bearing Trees, like the Alder and the Birch, increase. The limited growing seasons make for a more restricted accumulation of tissue. Such tropic plants as have braved the rigours of the colder climates have dwindled much in size. The Castor Oil Tree becomes a humble annual (_Ricinus Communis_) only three to eight feet in height. Other tropical trees become so small that temperate zone folk tread them under foot.