Page:Popular Science Monthly Volume 63.djvu/429

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HE close connection between pulse and rhythm has been speculated upon since the fourth century before Christ. Herophile, Avicenna, Savonarola, Saxon, Fernel and Samuel Hafen-Refferus have successively conjectured that the rhythmic phenomenon of pulse is in some way responsible for our sense of 'beat.' The speculation was fascinating. It could not become convincing without the help of data capable of being furnished only by very recently invented instruments and by recently accumulated knowledge.

A sense of rhythm, probably due to instinct, is found well developed low down in the animal series. This fact is significant when one considers that the theory usually advanced and accepted is that physical activities of a regularly recurrent nature have created this sense in man. The beat of the pestle used by primitive man to crush grain, the blows of the flail, the rhythm of the quern and the spinning wheel, the rock of the cradle, and in short the entire series of industries where a regular beat or reciprocal motion suggests alternate action have been put forward as the probable origin of the dance, musical and verbal rhythm, and at length of the beat of music.

Tempting as is this theory which associates the origin of rhythm with the development of ordered human activity, a rhythmic sound, call or cry is first found coexistent with the first complete circulatory system, heart with valves and blood vessels. This first appears in the insect family and there too, in the saltoria of the orthoptera (commonly known as crickets, grasshoppers and locusts) appears this conjunction of hearing, ability to call or stridulate, a nervous system and valvular heart. The common existence of these phenomena does not prove that the beat of the rudimentary insect heart led to rhythm, but it suggests, at least, that this combination has been subjectively fruitful of recurrent sound as a form of sexual and probably of pleasurable activity.

Mr. S. H. Scudder has put down the songs of these little creatures in musical notation, giving them after careful consideration the attribute of rhythm. Unfortunately the circulatory system of the insect world