. The anatomy of woody plants. Botany -- Anatomy. 422 THE ANATOMY OF WOODY PLANTS higher latitude of annual rings and their absence in the lower one. On the other hand, in the beginning of the Mesozoic (the Triassic) even at a distance of 10 degrees south of the latitude of Prince Edward Island annual rings were quite clearly developed. Without considering the Jurassic we may pass at once to the end of the Mesozoic period, namely, the Upper Cretaceous. Fig. 291 reproduces the organization of the wood of a Cretaceous araucarian conifer closely allied to, if not identical with, the living kauri
. The anatomy of woody plants. Botany -- Anatomy. 422 THE ANATOMY OF WOODY PLANTS higher latitude of annual rings and their absence in the lower one. On the other hand, in the beginning of the Mesozoic (the Triassic) even at a distance of 10 degrees south of the latitude of Prince Edward Island annual rings were quite clearly developed. Without considering the Jurassic we may pass at once to the end of the Mesozoic period, namely, the Upper Cretaceous. Fig. 291 reproduces the organization of the wood of a Cretaceous araucarian conifer closely allied to, if not identical with, the living kauri (A gat his). A per- sistent leaf trace appears running through the figure transversely. The wood is considerably over half a century (as recorded in annual rings) from the center of the stem, and the foliar strand still persists in the manner characteristic of re- lated living arau- carian genera. The yearly increments of growth are distinctly indicated, although not very strongly marked. For comparison with the above illustration a photograph of the wood of Agathis australis from New Zealand is shown in Fig. 292. Here annual rings are clearly apparent, although the latitude in the Southern Hemisphere is nearly the same as the place of origin of the Cretaceous araucarian wood above, namely, 40 degrees. It is thus apparent that the Cretaceous of Staten Island was marked by a much less distinct annual variation of temperature than is the South Island of New Zealand of today, although the two localities are of almost identical latitude. Without pursuing the. FIG. 291.—Transverse section of an Araucarioxylon from the Cretaceous of Staten Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Jeffrey, Edward C. (Edward Charles), b. 1866. Chicago, Ill. , The University of Chicago Press
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