. Foundations of botany. ONS OF BOTANY 300. Organs for Repro-duction. — The fruitingorgans are to be soughton the radiating branchingfilaments and are usuallyproduced in great abun-dance during the stages of develoj>ment may be expected ata given time. The anther-ozoids are small sphereswithout cilia, non-motile,with a thin cell-wall. Lookfor cells in which they areformed (antheridid), occur-ring in groups at the tipsof the branches. Comparethese with the vegetativecells. 301. Spore-Production.— Look for spore-producingorgans in various the young stage at thetime of
. Foundations of botany. ONS OF BOTANY 300. Organs for Repro-duction. — The fruitingorgans are to be soughton the radiating branchingfilaments and are usuallyproduced in great abun-dance during the stages of develoj>ment may be expected ata given time. The anther-ozoids are small sphereswithout cilia, non-motile,with a thin cell-wall. Lookfor cells in which they areformed (antheridid), occur-ring in groups at the tipsof the branches. Comparethese with the vegetativecells. 301. Spore-Production.— Look for spore-producingorgans in various the young stage at thetime of fertilization, an-therozoids, carried by cur-rents of water, may befound adhering. Kote theshape of the tip (trichogyne)and the base (carpogoniuni),and find whether there isany partition separatingthem at this stage. Drawor describe a few laterstages in development, andnote the arrangement of the spores at maturity. Are they naked or enclosed in any sort ofenvelope? Are they arranged in masses, chains, or otherwise?. Fig, 187. — Portions of Tliallus of a Red Alga(Chantransia). (Much magnified.) A, filaments with antheridia, a ; B, young recep-tive hair, or trichogyne, t; C and D, successivestages in the growth of the clustered fruit,/. TYPES OF CRYPTOGAMS; THALLOPHYTES 255 302. Other Florideae. — Nemalion represents one of the simplestmodes of fruiting in the red algse. In others there is great variety instructure and great complication in the mode of fruiting. Somespecies of Polysiphonia (or Dasya) may well be studied in compari-son with Nemalion and in fui*ther illustration of this importantgroup.^ Understanding that a siphon, in algse, is a row of cells, endto end, study the structure of a plant of Poly-siphonia as illustrating its name. How manysiphons are there? Do the main brancheshave any other cells covering the surface (cor-ticating cells) ? Note the tufts of repeatedly forking, one-siphoned filaments. 303. Fruiting of Polysiphonia. — The anther-idia are to
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