. Botany for agricultural students . Botany. 322 THALLOPHYTES smaller. Although strictly aquatic, they produce no zoospores and their sexual reproduction is much specialized. Rockweeds. — These are very common Seaweeds and are especially abundant on rocky shores. The plant body, sometimes a foot or more in length, is much branched and has bladder- like floats and commonly special reproductive structures. The Rockweeds are common in fish markets, being used as a packing. Fig. 278. — Reproduction in Fucus vesiculosus. a, section through a swollen tip, showing sections through some of the concept
. Botany for agricultural students . Botany. 322 THALLOPHYTES smaller. Although strictly aquatic, they produce no zoospores and their sexual reproduction is much specialized. Rockweeds. — These are very common Seaweeds and are especially abundant on rocky shores. The plant body, sometimes a foot or more in length, is much branched and has bladder- like floats and commonly special reproductive structures. The Rockweeds are common in fish markets, being used as a packing. Fig. 278. — Reproduction in Fucus vesiculosus. a, section through a swollen tip, showing sections through some of the conceptacles; b, much enlarged section through an oogonial conceptacle, showing the pore-like open- ing to the exterior and the oogonia within; c, a similar section through a conceptacle containing antheridia which appear as small bodies on the fila- ments projecting from the walls of the conceptacle; d, antheridia much en- larged and one antheridium shedding its sperms; e, oogonium from which the eggs are escaping; /, sperms swarming around an egg. in the shipment of crabs and other shell fish. Along the west coast of South America and also in other countries, Fucus is used for food by the inhabitants, and it is also used as a fertilizer and as a source of iodine. Fucus vesiculosus, one of the commonest of the Rockweeds, will serve to illustrate the character of the plant body and the peculiar features of reproduction, the former being shown in Figure 277 and the latter in Figure 278. The gametes are differentiated. 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
