Text-book of botany, morphological and physiological . ewalls of the compartments begin in a short time(about 10 minutes) to swell so violently that firstof all the testa is split along the ventral edgeinto two valves, the annular cushion detachingitself from the inner surface of the testa, en-larging in consequence of the swelling, and protruding from the slit in the form of aring (Fig. 300 B). The compartments of the sporocarp are attached at both ends to theinner periphery of this ring; but they are all torn off on one side by its gradual expan-sion ; it now stretches to a great size, incre
Text-book of botany, morphological and physiological . ewalls of the compartments begin in a short time(about 10 minutes) to swell so violently that firstof all the testa is split along the ventral edgeinto two valves, the annular cushion detachingitself from the inner surface of the testa, en-larging in consequence of the swelling, and protruding from the slit in the form of aring (Fig. 300 B). The compartments of the sporocarp are attached at both ends to theinner periphery of this ring; but they are all torn off on one side by its gradual expan-sion ; it now stretches to a great size, increasing at the same time in thickness, andusually subsequently breaks, as shown in Fig. 300 C, unrolling into a straight or vermi-form linear body, and bearing the alternating compartments of the sporocarp in con-tiguous pairs. Each of these compartments contains on its outer side the projectingridge on which the sporangia grow {D, E); both the macrospores and microsporesescape from the sporangia and from the sac of the sporocarp which envelopes them ;. 300. — Marsilea salvatrjx; A a sporocarp(natural size), st the upper part of its pedicel; B asporocarp which has burst in water and is protrudingits gelatinous ring (after Hanstein); C the gelatinousring g- ruptured and extended, sr compartments ofthe sporocarp ; sch testa of the sporocarp; D a com-partment of an unripe sporocarp with its sporangia;E one from a ripe sporocarp; ?>ni microsporangia,ma macrosporangia. ^.00 VASCULAR CRYPTOGAMS. their outer gelatinous envelope, which surrounds the exospore, swelling up. Theirsize being thus increased, they glide out, and escape into the surrounding water, wherethe germination of Marsilea sal-vatrix begins and completes its course with extraordinaryrapidity. With a favourable summer temperature, antherozoids and archegonia readyfor fertilisation are formed within 12 or 18 hours. Hanstein was the first to de-scribe these processes accurately; I have myself repeatedly seen them
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectbotany, bookyear1875
