Page:The Harveian oration - delivered at the Royal College of Physicians, London, on October 18, 1884 (IA b21778929).pdf/26

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and that of the "sensorium commune," that there are some actions and motions the government or direction of which is not dependent on the brain that there is a certain sense or form of touch (meaning contact, or impres - sion) which is not referred to the common sensorium, nor in any way communicated to the brain, so that we do not perceive by this sense (i.e. impression) that we feel 23"} and this sense we therefore distinguish from the proper animal sense." Harvey termed it a "natural sense,' as distinguished from " animal sense;" and he continues, "such a sense do we observe in zoophytes or plant animals, in sponges, the sensitive plant, &c." Using the word "sense with this interpretation, he treats of many animals, "who are endowed with both sense and motion without having a common sensorium or brain . . . . so also [he adds] do certain natural actions take place in the embryo, and even in ourselves, without the agency of the brain, and a certain sensation takes place without consciousness." After speaking of the difference to be observed between "regulated contractions and relaxations to perform any movement, such as progression or prehension," he compares these movements to "the muscles or organs of motion, when affected with spasms or convulsions from an irritating cause," and points out their resemblance to those of "the decapitated cock or hen the convulsive movements of the legs and wings, but all confused and without a purpose, be- cause the controlling power of the brain has been taken away."

The explanation of these movements given by Harvey-viz., that they "proceed from the power of the heart, and depend on it," is certainly not true in the sense in which he intended it, but he gives a most interesting illustration of his physiological insight when he says, "We have an excellent example of both these kinds of motion (animal and