The Evolution Of Plant Life; Lower Forms

Paperback | January 16, 2012

byGeorge Massee

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This historic book may have numerous typos, missing text or index. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. 1891. Not illustrated. Excerpt: ... CHAPTER III. Subdivision II.--THALLOPHYTA. Class I.--Algm Seaweeds). Protophyta--Primordial Types of Plant Life--Transition from Unicellular through Cell Colonies to Multicellular Plants--. Earliest Indications of Sexual Reproduction--Terminal Groups of Protophytes--Algee Proper--Gradual Differentiation of Vegetative and Reproductive Parts---Evolution of new Groups--Distribution--Fossil Algae. (A) Protophyta. The Protophyta, as the name denotes, includes the primordial types of plant life, and are often considered as belonging to the Algae, but are treated by Bennett as a distinct subdivision. This author states, however, that "whether the Protophyta should be reckoned as a distinct subdivision from the Algae, or only as the lowest members of that great series, is a question rather of convenience than of principle." The great bulk of forms included in the present class are unicellular, without a distinct process of sexual reproduction, and are either destitute of chlorophyll, or this substance may be present in a pure form, or its characteristic green colour masked by the additional presence of blue or brown colouring matter. Although the above characters may be considered as characteristic of the Protophyta, we nevertheless meet with indications of the multicellular type of structure, and also of the simplest form of sexual reproduction by conjugation. Class I.--Schizomycetes Bacterid). The exceedingly minute size of the cells constituting the members of the present group preclude an exact study of their nature. With very rare exceptions chlorophyll is absent; hence they are either saprophytes or parasites. In one species, Beggiatoa roseo-persicina, a red colouring matter tinges the protoplasm, and in many other examples, in certain stages of development, brigh...

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This historic book may have numerous typos, missing text or index. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. 1891. Not illustrated. Excerpt: ... CHAPTER III. Subdivision II.--THALLOPHYTA. Class I.--Algm Seaweeds). Protophyta--Primordial Types of Plant Life--Transition from Unic...

Format:PaperbackDimensions:68 pages, 9.69 × 7.44 × 0.14 inPublished:January 16, 2012Publisher:General Books LLCLanguage:English

The following ISBNs are associated with this title:

ISBN - 10:0217292860

ISBN - 13:9780217292863

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