The co-ordination of insect movements. I. The walking movements of insects

Though walking forms part of many insect behaviour patterns, the mechanism of insect walking has received relatively little attention in recent years. As a pre-liminary to a later investigation of neuromuscular co-ordination in insects, the normal pattern of walking movements in the cockroach and other insects has been studied. The results obtained and an account of the functional anatomy of the insect leg are given in this paper. The forces involved have not been measured, but a preliminary analysis of the mechanics of walking has been made with the help of 'stills ' from cinematographic films. The use of cinematography greatly facilitates such an investigation. Borelli (1680), in his De motu animaUum, did not give a true picture of insect leg movements, but his suggestion concerning their order of protraction has been substantiated in the present research. In reviewing Borelli's account, Demoor (1890) was very critical of the supposition that it would be advantageous if the three ipsilateral legs of a hexapod were lifted in the order ' initium motus fieret a posteriori, cui succederet medius et ultimo anticus'. This suggestion was based not on ob