A muscle-domain hypothesis forAscarispostural waves

Abstract

A hypothesis to explain some features of Ascaris flexures is given. It is based on the co-operation of muscle cells in domains which may assume two states. In one state the muscles are long and it is mainly the non-contractile parallel elements that are in tension. The other state has short muscles exerting tension mainly in the contractile elements. The living animal changes shape if new domains are formed or if domain boundaries move. The hypothesis is applied to laboratory experiments and observations.