. Botany for high schools. Botany. 3o8 GENERAL MORPHOLOGY OF PLANTS 474. The male plants and sperm cases (antheridia).—The sperm cases are borne on special outgrowths, the gamete bearer.* These are disk-shaped and stalked. The sperm cases are in flask-shaped cavities of the upper surface. Each sperm case is a more or less oval body like a stalked capsule with a wall of a single layer of cells. The interior is a mass of minute cells in each of which t^vo sperms are formed. Each sperm is a long, slender body, with two long, very slender cilia which lash about and cause it to move in the water. 4
. Botany for high schools. Botany. 3o8 GENERAL MORPHOLOGY OF PLANTS 474. The male plants and sperm cases (antheridia).—The sperm cases are borne on special outgrowths, the gamete bearer.* These are disk-shaped and stalked. The sperm cases are in flask-shaped cavities of the upper surface. Each sperm case is a more or less oval body like a stalked capsule with a wall of a single layer of cells. The interior is a mass of minute cells in each of which t^vo sperms are formed. Each sperm is a long, slender body, with two long, very slender cilia which lash about and cause it to move in the water. 475. The female plant and egg cases (archegonia).—The egg cases or female organs are also borne on special outgrowths, the gamete bearers. The egg gamete bearer is shaped some- thing like the sperm gamete bearer, Fig- 283. but the disk is divided into slender Section of antheridium of Mar- chantia, showing the groups of rayS and sperm mother cciis. the stalk is longer, giving it an umbrella shape (fig. 285). The egg cases are borne on the under surface of the disk, between the delicate, thin, laminate tissues which hang downward and protect them from drying out. Each egg case is a flask-shaped structure with a swol- len base {venter)^ and a long, slender neck with a canal leading^ Fig. 284. Sperms of Marchantia uncoihng down to the eerg in the basal part, and one extended, showing the two ^ ciUa. When the egg is ripe the canal opens, and if a sperm enters and passes into the egg, it unites with the egg nucleus and fertilization 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 Atkinson, George Francis, 1854-1918. New York, H. Holt and Company
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1910
