The Mechanism of Locomotion in Snakes

Abstract

ABSTRACT Among snakes four main types of terrestrial progression have been described: (i) serpentine movement which is observable in all, or nearly all, genera; (ii) concertina movement as briefly described by Wiedemann (1932) in Vipera and Coronella; (iii) crotaline or ‘side-winding’ as seen in Crotalus or Cerastes (Mosauer, 1932a,b); and (iv) rectilinear movement as exhibited by boas and other large types (Home, 1812). The observations described in the present paper have all been made on the common grass snake (Tropidonotus natrix); the evidence to be presented shows that serpentine, concertina or crotaline movements can all be elicited in this genus by appropriate modification of the external forces operating on the body of the moving animal.