Forced Movements, Tropisms, and Animal Conduct

Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. Sin certain muscles of one side of the body than in the symmetrical muscles of the other side, and the animal will no longer move in a straight lined The only difference between the forced movements induced by unequal illu mination of the two eyes and by injury to the brain is that in the latter case the forced movements may last for days or throughout the whole life, while in the former case they last only as long as the illumination on the two sides of the body is unequal. If we bring about a per manent difference in illumination in the eyes, e.g., by blackening one eye in certain insects, we can also bring about permanent circus motions. This shows that animal conduct may be justly designated as consisting of forced; movements.