Page:Life in Motion.djvu/108

From Wikisource
Jump to navigation Jump to search
This page has been validated.
88
LIFE IN MOTION

carefully the facts on which they founded their theories. Thus the Hallerians recognised that contractile movement occurred in other tissues than in muscle alone, as in the coats of the arteries and in the skin; whilst, on the other hand, their opponents were led to study more carefully the physiology of the nervous system. Thus the dispute contributed to clearer physiological ideas apart from the real question at issue.

Time has declared in favour of Haller. His opponents naturally pointed to the wasting of the muscles after division of the nerves supplying them; but, on the other hand, it has been shown that this is due to the imperfect nutrition which follows a state of inaction, and that if the nerve or muscle be directly and systematically stimulated, the muscle may not undergo very much degeneration nor become less irritable. We know also that we may exhaust a nerve so that when shocks are applied to it the muscle with which it is connected will not respond. If we then send the shock directly to the muscle it may still contract. Again, the protoplasm of plants, and of many of the lower forms of animal life