An attempt is made here to avoid such incongruities. Groups X, XI and XII represent different stages of evolution. In the Lariciones the cone is symmetrical, and dehiscent and deciduous at maturity, while the spring-shoot is uninodal. In the Australes there is a similar cone, but the spring-shoot gradually becomes multinodal. In the Insignes the cone is oblique, persistent and serotinous, and the spring-shoot is multinodal. These definitions state the degree of evolution attained by each group, but not all the species of a group conform exactly with its definition. In each group are species with a characteristic of another group. Among the Lariciones are a few species with both symmetrical and oblique cones, and two with persistent cones. Similar exceptions occur among the Australes. Among the Insignes are a few species with symmetrical cones, and two with cones that are rarely, if ever, serotinous. There is, however, no difficulty in fixing the systematic position of these exceptional species through other characters which show their true affinity. They are placed with the species which they most resemble. Their exceptional characters are merely the evidence of the evolution that pervades and unites the groups. Therefore the definition of a group is not necessarily the exact definition of its species, and a species is placed in a group because all its characters, specific and evolutional, show a closer affinity with that group than with the species of any other. =X. LARICIONES= Pits of the ray-cells large. Cells of the leaf-hypoderm uniform. Spring-shoots uninodal. Cones dehiscent at maturity. This group represents the first stage in the evolution of the Hard Pines. All the species, like the Soft Pines, are uninodal and the cones are dehiscent at maturity, but the trend toward the serotinous species is shown in the occasional appearance of the oblique cone as a varietal form of a few species, and in the persistent cone of the last two species of this group. All the species of this group are of the Old World except P. resinosa and P. tropicalis. These two are the only American Pines combining large pits with dentate tracheids, and are the only American Hard Pines with external resin-ducts of the leaf.