In the chapter on “How Plants Produce Their Young,” we found that most flowering plants have their ovules in an ovary which, after fertilization, develop into fruit and seed. But some plants, while they have ovules, only bear them naked or between scales, never inclosed in an ovary. This is true in all pines, spruces, hemlocks, and all the host of their generally evergreen relatives. Such trees bear cones, between the scales of which are perfectly naked ovules that develop into seeds (Figure 77) that have never been hidden in an ovary, as have the vast majority of the seeds of other plants (Figure 53). These naked-seeded plants are known as _gymnosperms_ or literally _gymnos_, naked, and _sperma_, seed, and comprise all the cone-bearing trees in the world, the larger part of which are always evergreen. In some past ages such trees made up the bulk of vegetation of the earth, but at present they are much reduced in numbers. Familiar examples of these _Coniferæ_, or cone-bearing trees, are larch, spruce, fir, pine, hemlock, juniper, and yew. [Illustration: FIG. 77.--THE JERSEY PINE (_Pinus virginiana_) A gymnosperm or naked-seeded plant. Note the seeds dropping from between the scales of the cone.] Most of these are evergreen, which does not, of course, mean that they bear the same leaves always, but that only a few drop off at a time and are so constantly renewed that the tree is actually ever green. All other flowering plants always bear their ovules in an ovary and, because of this fact, are called _angiosperms_, literally _angeion_, a vessel, and _sperma_, seed. These inclosed seeded plants comprise the great bulk of the vegetation of the earth to-day. So far as the temperate zone is concerned, nearly all of them drop their leaves in the fall, and the trees belonging to the angiosperms are thus said to be deciduous trees. No better idea of the present size and importance of these two groups of plants can be gained than to state the fact that perhaps not over 500 different kinds of gymnosperms, all of which are trees and shrubs, are known. All the rest of the flowering plants in the world, comprising over 150,000 different kinds of herbs, shrubs, and trees of infinite variety, are angiosperms and therefore bear ovules in an ovary, followed by seeds in or on some sort of a fruit. It would almost seem as though the simplest way to dispose of this great mass of plants would be to sort them into trees, shrubs, and herbs. For all of them belong to one of these types of plant growth, and the ancient students of plants, just before the time of Christ, actually divided all flowering plants into these three classes. This, of course, threw the coniferous trees in with all other kinds and, as we have already seen, they differ from all other kinds in the important character of having naked ovules.