Plant-life, with 74 full-page illus., 24 being from photos, by the author and 50 in colour from drawings . cent Period of the Palaeozoic Era—thePermian—we find signs of change; indeed, the PermianPeriod was one of marked transition. Ferns as a groupheld their own, as they have done even to modern times;but the other groups, so dominant in Carboniferoustimes, began and continued to dwindle. The Conifers(p. 180), dominant among modern Gymnosperms, canbe traced back with certainty to Permian times, and itis possible that in Walchia, of which fossils of leafytwigs, with a habit resembling that of
Plant-life, with 74 full-page illus., 24 being from photos, by the author and 50 in colour from drawings . cent Period of the Palaeozoic Era—thePermian—we find signs of change; indeed, the PermianPeriod was one of marked transition. Ferns as a groupheld their own, as they have done even to modern times;but the other groups, so dominant in Carboniferoustimes, began and continued to dwindle. The Conifers(p. 180), dominant among modern Gymnosperms, canbe traced back with certainty to Permian times, and itis possible that in Walchia, of which fossils of leafytwigs, with a habit resembling that of certain modernAraucarias, are frequently found, we have evidence ofConifers in the higher Carboniferous strata. Formsallied to living genera of Conifers occur in Permian rocks,and these seem to have increased as the Period an age when the great Carboniferous groups werewaning, the Conifers were enlarging the place of theirtent, and at the same time a new group—the Ginkgo ales—were coming into prominence. As I have alreadystated (p. 233), the genus Ginkgo has now but one Plate GARLIC MUSTARD, or JOCK-BY-THE-HEDGE (Sisymbrium alliaria).Order CRUCIFERjE. 1. Plant with young flower 2. Older flower 3. Fruit MESOZOIC PLANTS 245 species —the Maidenhair Tree. Oriental reverencehas saved it from extinction, and the curiosity of theOccident is securing its cultivation over a wide species has a peculiar botanical interest as thesole survivor of a gymnospermous group of numerousspecies, the oldest of which date back to the Permian,and as an instance of a Gymnosperm in which theovule, after the manner of Cycas, is fertilized by anactively swimming male cell (p. 178). The Ginkgoalesreached the hey-day of their development in theMesozoic. The Mesozoic Era, embracing the Triassic, Jurassicand Cretaceous Periods—the geological Middle Ages —was undoubtedly the Era of Gymnosperms. Fernsheld their own, but the cryptogamic Lycopods andHorsetails, so majesti
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1915
