. Botany for agricultural students . Botany. SSGSSSSSSQ Fig. 335. — A much en- larged section through a Fig. 334. — A much branched Lichen, showing the fungal Lichen hanging from the branch hyphae and the globular cells of a tree. of the Alga. the Alga nor the Fungus could grow in such places alone, for the Alga would lack moisture and the Fungus would lack food. Being so little dependent upon their support for moisture and food, the Lichens are the pioneers on bare and exposed surfaces. They hasten the disintegration of rock and start soil formation. The materials of their dead bodies added t
. Botany for agricultural students . Botany. SSGSSSSSSQ Fig. 335. — A much en- larged section through a Fig. 334. — A much branched Lichen, showing the fungal Lichen hanging from the branch hyphae and the globular cells of a tree. of the Alga. the Alga nor the Fungus could grow in such places alone, for the Alga would lack moisture and the Fungus would lack food. Being so little dependent upon their support for moisture and food, the Lichens are the pioneers on bare and exposed surfaces. They hasten the disintegration of rock and start soil formation. The materials of their dead bodies added to the disintegrate rock form a soil for other plants. Lichens multiply vegetatively by small scale-like portions, called soredia, which separate from the main plant body. Soredia are small masses of hyphae in which some algal cells are en- tangled and are capable of growing directly into Lichens. The fungal member of Lichens usually reproduces by asco- spores and the algal member by cell division. The asci occur in ascocarps which appear as small cups or disk-like bodies on the surface of the plant body {Fig. 336). The sex organs are quite suggestive of the Red Algae. The antheridia occur on branching hyphae and are very small cells which break off and function as sperms. After fertilization, sterile hyphae grow up from below the ascogonium and form the wall of the ascocarp which finally. 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 Martin, John N. (John Nathan), b. 1875. New York : John Wiley & Sons, Inc.
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1919
