If the period just after plants were first known on the earth may be called the Reign of Algæ, and subsequent periods were typified by still other kinds of plants, then our present period is _par excellence_ the reign of flowering plants. In numbers of individuals they are still far outclassed by such cryptogams as the fungi, bacteria, algæ, etc., but their dominating influence in the plant world is unquestioned. While all our present vegetation must have been derived from preexisting types, all of it is not necessarily directly descended from species which from their fossil records we know to have existed in geological periods older than our own. While the fossil record of the times immediately preceding the last ice age is a much more complete one than for many other periods, it fails to account directly for the great bulk of our varied flora of to-day. While ferns in great variety, gymnosperms, and hundreds of flowering plants are known quite definitely, they total only a minute fraction of these groups to-day. Even granting the always imperfect nature of the fossil record, and we have seen what an accident the formation of a plant fossil may be, and it is common knowledge how few comparatively have ever been recovered--even granting all this, there still remains a large part of our present flora of which the origin probably dates from comparatively recent times. So overwhelmingly true is this that of the Compositæ, or daisy, family, now numbering over 11,000 species, scarcely a handful of fossil species have been found. And in all collections of fossils the woody plants far outnumber the herbs, perhaps because of the greater probability of their being thus preserved rather than to any actual scarcity of herbs in the upper strata. And yet herbs to-day outnumber woody species over two to one. While it is true, then, that our present flora must have been derived from preexisting races, it is also true that much of it is apparently derived from plants that do not date very far back into the past. A few main _types_ of flowering plants unquestionably are to be linked with fossil genera, but these types have now branched out into a wealth of detail that may not have existed and is certainly not recorded in the fossil record.