. Lectures on the evolution of plants. Botany; Plants. ALG^ 57 The exact affinities of many of the Siphoneae are still obscure, and it is by no means impossible that the group has had a multiple origin, all the members of the order may not neces- sarily be genetically related, but there may have been a develop- ment of this peculiar type from several an- cestral forms. While the lowest of the or- der show much in common vi^ith the Protococcacese, and may, perhaps, have arisen from them, others like the com- mon genus Vaucheria (Fig. 12) are struct- urally more like some of the Confer- vac
. Lectures on the evolution of plants. Botany; Plants. ALG^ 57 The exact affinities of many of the Siphoneae are still obscure, and it is by no means impossible that the group has had a multiple origin, all the members of the order may not neces- sarily be genetically related, but there may have been a develop- ment of this peculiar type from several an- cestral forms. While the lowest of the or- der show much in common vi^ith the Protococcacese, and may, perhaps, have arisen from them, others like the com- mon genus Vaucheria (Fig. 12) are struct- urally more like some of the Confer- vaceae. There are a number of genera among the latter where the elongated cells are multinucle- ate and there is a partial suppression of the division walls, nuclear division and cell division being quite indepen- dent of each other. By the complete suppression of the division walls in forms like these, it is conceivable that. 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 Campbell, Douglas Houghton, 1859-1953. New York, The Macmillan Co. , London, Macmillan & Co. , Ltd.
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Keywords: ., bookcentury1800, bookdecade, booksubjectbotany, booksubjectplants
