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I am not now alluding to such phænomena, at once rare and conspicuous, as those exhibited by the leaflets of the sensitive plant, or the stamens of the barberry, but to much more widely-spread, and, at the same time, more subtle and hidden, manifestations of vegetable contractility.
The inflammation and tumefaction of the parts continued for a considerable time, and when ultimately reduced by the application of tepid fomentations, the skin appeared greatly relaxed; and the muscular fibres having lost their power of support or contractility, owing to their long quiescence, seemed no longer able to keep their lids in their proper situation; the edges therefore remained in the abnormous position previously assumed.
Close observation of the newly- opened lobster would soon show that all its movements are due to the same cause the shortening and thickening of these fleshy fibres, which are technically called muscles. Here, then, is a capital fact. The movements of the lobster are due to muscular contractility. But why does a muscle contract at one time and not at another?
Neither mirror, nor burned feather, nor ammonia, nor pricking succeeded in giving us a sign of sensibility. Galvanism was tried without the patient showing any contractility. Mr. Franck believed her to be dead, but nevertheless advised me to leave her on the bed. For twenty-eight hours no change supervened, although it was thought that a little putrefaction was observed.
Close observation of the newly opened lobster would soon show that all its movements are due to the same cause the shortening and thickening of these fleshy fibres, which are technically called muscles. Here, then, is a capital fact. The movements of the lobster are due to muscular contractility. But why does a muscle contract at one time and not at another?
The muscular tissue is the most abundant of all the tissues, forming about 41 per cent of the weight of the body. *Properties of Muscles.*—The ability of muscular tissue to produce motion depends primarily upon two properties—the property of irritability and the property of contractility.
The protoplasm of Algae and Fungi becomes, under many circumstances, partially, or completely, freed from its woody case, and exhibits movements of its whole mass, or is propelled by the contractility of one, or more, hair-like prolongations of its body, which are called vibratile cilia.
The protoplasm of Algæ and Fungi becomes, under many circumstances, partially, or completely, freed from its woody case, and exhibits movements of its whole mass, or is propelled by the contractility of one, or more, hair-like prolongations of its body, which are called vibratile cilia.
"To apply the physical sciences to physiology is to explain the phenomena of living bodies by the laws of inert bodies. Now this is a false principle, hence all its consequences are marked with the same stamp. Let us leave to chemistry its affinity; to physics, its elasticity and its gravity. Let us invoke for physiology only sensibility and contractility."
We saw that in primitive tribes, as in the simplest animals, there remains much community of function between the parts which are nominally different that, for instance, the class of chiefs long remains industrially the same as the inferior class; just as in a Hydra, the property of contractility is possessed by the units of the endoderm as well as by those of the ectoderm.
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