Page:Life in Motion.djvu/118

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LIFE IN MOTION

spending nerve-fibre. The number of nerve-fibres must therefore be enormous, and a recognition of this fact gives rise to several curious considerations which I shall discuss when we come to consider the electric fishes.

Now we are in a position again to approach the question whether or not the irritability Fig. 51.—Motor nerve-ending from the muscular fibre of the intercostal muscle (muscle between the ribs) of a hedgehog. N, nerve; P, end-plate; Z, flat connective tissue-cells. of a muscle is inherent in the muscle-fibre. Suppose we could eliminate altogether the nerve-fibres in a muscle, would the muscular substance then contract if we irritated it? From what I have told you, you will admit that we could not mechanically remove all the nerve-twigs from a muscle. They are too small to be manipulated by the most dexterous