. Foundations of Botany. Botany. 254 FOUNDATIONS OF BOTANY 300. Organs for Repro- duction. — The fruiting organs are to be sought on the radiating branching filaments and are usually produced in great abun- dance during the summer. Various stages of develop- ment may be expected at a given time. The anther- ozoids are small spheres without cilia, non-motile, with a thin cell-wall. Look for cells in which they are formed (aniheridia), occur- ring in groups at the tips of the branches. Compare these with the vegetative cells. 301. Spore-Production. —Look for spore-producing organs in various sta
. Foundations of Botany. Botany. 254 FOUNDATIONS OF BOTANY 300. Organs for Repro- duction. — The fruiting organs are to be sought on the radiating branching filaments and are usually produced in great abun- dance during the summer. Various stages of develop- ment may be expected at a given time. The anther- ozoids are small spheres without cilia, non-motile, with a thin cell-wall. Look for cells in which they are formed (aniheridia), occur- ring in groups at the tips of the branches. Compare these with the vegetative cells. 301. Spore-Production. —Look for spore-producing organs in various stages. In the young stage at the time of fertilization, an- therozoids, carried by cur- rents of water, may be found adhering. Note the shape of the tip (trichogyne) and the base (carpogonium), and find whether there is any partition separating them at this stage. Draw or describe a few later stages in development, and note the arrangement of the spores at maturity. Are they naked or enclosed in any sort of envelope? Are they arranged in masses, chains, or otherwise?. Fig. 187. —Portions of Thallus of a Red Alga (Chantransia). (Much magnified.) A, filaments with antheridia, a; B, young recep- tive hair, or trichogyne, t; C and D, successive stages in the growth of the clustered fruit,/.. 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 Bergen, Joseph Y. (Joseph Young), 1851-1917. Boston, Ginn & company
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbotany, bookyear1901
