The new international encyclopaedia . e from microscopic forms and delicate fila-mentous types (Ectocarpales) to the immensecoarse kelps several hundred feet Ion- The Laminariales (kelps, devils aprons) generallyhave a stalk (stipe) attached to the rocks bya cluster of strong root-like processes (hold-fast), that ends in an expansion called theblade, which in some forms bears lateral leaf-like structures. The blade is simple in thesmaller forms (Laminaria), or perhaps splitup longitudinally into segments. In manytypes the blade is cast off at certain periodsby the development of a new one thro
The new international encyclopaedia . e from microscopic forms and delicate fila-mentous types (Ectocarpales) to the immensecoarse kelps several hundred feet Ion- The Laminariales (kelps, devils aprons) generallyhave a stalk (stipe) attached to the rocks bya cluster of strong root-like processes (hold-fast), that ends in an expansion called theblade, which in some forms bears lateral leaf-like structures. The blade is simple in thesmaller forms (Laminaria), or perhaps splitup longitudinally into segments. In manytypes the blade is cast off at certain periodsby the development of a new one througli theactivity of the tissues below the old. Inother genera the blade serves as the growingregion of tlie plant, and splits olT segmentswhich take a lateral position on the stem (Macro-cystis). The most interesting forms on the Americancoast are the giant kelps of the Pacific Ocean,ilacrocystis is reported to attain a length of 900feet. It is easily recognized by the leaves borneon a stem about the size of a clothes line. Par. FlQ. 1. BROWN ALG,€. 1. Ectocarpus. with p:anietes escaping? ; 2, conjugation ofthe same, showing {a) niimeroua male gametes about asingle (emale gamete, and (h) various stages of fusion; 3,Pylaieila, with one cell functioning as a sporangium. more picturesque is the sea-otters cabbage(Xereocystis), which consists of a flexible leaf-less stalk swollen at the end into a hollowspherical float several inches in diameter. Thetop of the float bears long strap-like leaves thatextend on either side in the water, and arewhipped about by the wind and surf. Anotherinteresting form is the sea-palm (Postelsia),which grows on surf-beaten rocks and reefs, andhas a heavy, thick, erect stalk 12 to 18 incheshigh, with a thick crown of leaves that grow-out and bend downward in the form of the con-ventional palm tree. The stalk is so tough thatit may be bent over at right angles by the forceof the waves without breaking. Lessonia, foundon the coast of Chile, has s
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