. The sea-beach at ebb-tide : a guide to the study of the seaweeds and the lower animal life found between tidemarks . In,, 11,i ;il,,ni! one toiirlli natural size. 138 MARINE INVERTEBRATES. Strobila of Aurelia flavidnla. the end of July they are fully developed, and begin to discharge their eggs,which go into the folds around the mouth and remain there until they at-tain the planula stage. After the spawningperiod the medusae, reduced in strength, areunable to resist the storms of the autumn,and many of them are cast ashore; manyothers, in a more or less wasted condition,float
. The sea-beach at ebb-tide : a guide to the study of the seaweeds and the lower animal life found between tidemarks . In,, 11,i ;il,,ni! one toiirlli natural size. 138 MARINE INVERTEBRATES. Strobila of Aurelia flavidnla. the end of July they are fully developed, and begin to discharge their eggs,which go into the folds around the mouth and remain there until they at-tain the planula stage. After the spawningperiod the medusae, reduced in strength, areunable to resist the storms of the autumn,and many of them are cast ashore; manyothers, in a more or less wasted condition,float near the surface, but the body is lesstransparent, its tissues are thickened, itstentacles gone, and general dissolution hascommenced. In this condition the medusaeare frequently capsized by the air which ac-cumulates in the empty egg-cavities, and,floating helplessly on the surface, are at-tacked and destroyed by swarms of smallcrustaceans; thus their cycle of life is ter-minated. It has been suggested that thedestruction of the mothers, by being cast upon the beaches in the autumnal gales, is a provision to set free theplanulse in a position favorable to their existence; for when liberated they f
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectmarinea, bookyear1901
