On the other hand, there are not wanting scientists who consider the _Abietineæ_ the living representatives of the most primitive and ancient stock, though on the whole the evidence seems to indicate more clearly that the Pine-tree group is specialized and highly modified. Their double series of foliage leaves, their complex cones (whose structures are not yet fully understood), and their wood all support the latter view. Some, again, consider the _Taxeæ_ as a very primitive group, and would place them near the Cordaiteæ, with which they may be related. Their fleshy seeds, growing not in cones but on short special axes, support this view, and it is certainly true that in many ways the large seeds, with their succulent coats and big endosperm, are much like those of the lower Gymnosperms and of several fossil types. Those, however, who hold to the view that the Abietineæ are primitive, see in the _Taxeæ_ the latest and most modified type of Gymnosperm. It will be seen from this that there is no lack of variety regarding the interpretation of Gymnosperm structures. The Gymnosperms do not stand in such an isolated position as do the Angiosperms. Whatever the variety of views held about the details of the relative placing of the families within the group, all agree in recognizing the evidence which enables us to trace with confidence the connection between the lower Gymnosperms and the families of ferns. There are many indications of the intimate connection between higher and lower Gymnosperms. Between the series exist what might be described as different degrees of cousinship, and in the lower groups lie unmistakable clues to their connection with more ancient groups in the past which bridge over the gaps between them and the ferns. For the present, however, let us confine ourselves to the history of the more important Gymnosperms, the discussion of their origin and the groups from which they may have arisen must be postponed until the necessary details about those groups have been mentioned. To a consideration of the living families of _Araucareæ_, _Abietineæ_, _Cupresseæ_, and _Taxeæ_ we can allow but a short space; their general characters and appearance are likely to be known to the reader, and their details can be studied from living specimens if they are not. For purposes of comparison with the fossils, however, it will be necessary to mention a few of the principal features which are of special importance in discussing phylogeny. The Araucariaceæ are woody trees which attain a considerable size, with broad-based, large leaves attached directly to the stem. In the leaves are a series of numerous parallel vascular bundles. The wood cells in microscopic section show two rows or more of round bordered pits. The cones are very large, but the male and female are different in size and organization. The female cone is composed of series of simple scales arranged spirally round the axis, and each scale bears a single seed and a small ligule.