The physiology of the circulation in plants : in the lower animals, and in man : being a course of lectures delivered at surgeons' hall to the president, fellows, etc of the Royal college of surgeons of Edinburgh, in the summer of 1872 . doubted. When the first instalment of the body is sentforward, it is Corrugated or gathered together (Fig. 121, c, a), andsecurely fixed on the ground by the assistance of the setee or hairssituated on the ventral aspect of the animal. A second inch or sois now elongated, telescopic fashion, and sent on precisely as in thefirst instance (Fig. 121, c, l>). T
The physiology of the circulation in plants : in the lower animals, and in man : being a course of lectures delivered at surgeons' hall to the president, fellows, etc of the Royal college of surgeons of Edinburgh, in the summer of 1872 . doubted. When the first instalment of the body is sentforward, it is Corrugated or gathered together (Fig. 121, c, a), andsecurely fixed on the ground by the assistance of the setee or hairssituated on the ventral aspect of the animal. A second inch or sois now elongated, telescopic fashion, and sent on precisely as in thefirst instance (Fig. 121, c, l>). The second instalment is not drawnforward, as is generally believed, but pushed forward, as the second instalment is gathered to the first, and both fixedto the ground by the setas, a third instalment is sent on, the wormnot beginning a second step until the tail instalment is forwardedand added to the body. The worm advances by a peristaltic or wavemovement. It pushes itself forward upon the ground, and in thisrespect resembles all other animals with terrestrial habits. If theworm had not the power of elongating and pushing its body forward,it is evident that it could never begin a step (Fig. 121, b, a). Figs. Fig. 121.—A represents the worm as drawn togetherprior to commencing a step, and divided intofour equal portions, a, b, c, d.— Original. B shows the first part of the worm as elongated or pushed out (a); the parts h, c, d, acting asfulcra.— Original. C shows the first part of the worm (a) shortened, corrugated, and fixed on the ground ; the second ?part of the worm (b) being elongated or pushed out; the parts c and d acting as fulcra.— Original. The movements of the worm are exceedingly interesting, asshowing that a muscular mass composed of circular and longitudinalfibres (each set continuous upon itself) has the power of elongating-even in the absence of fixed points. The locomotion of the wormis performed by two forces, which always act at
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectblo, booksubjectblood
