440 'Journal of Comparative Neurology and Psychology. 



Food Taking. — While locomotion is in the nature of a recoil, 

 in food taking this is not the case. Food is seized only when near- 

 by without preliminary movements. A glass capillary rod will 

 often be seized repeatedly by a hungry animal. Either a food 

 reaction or an avoiding reaction may be given if the rod is pre- 

 sented to either end. When it is presented at the posterior end, 

 in case the food reaction is given, the animal bends its head around, 

 and continuing to bend it moves directly to the object with a sud- 

 denness that is hard to follow (Fig. 4). If the rod is presented at 

 the side of the head it simply bends the head to one side, turning 

 on its long axis to get the object in its mouth. In both the food 

 reaction and the avoiding reaction the contraction of muscles 

 occurs on the stimulated side. But in the food reaction only the 

 head bends toward the object, while in the avoiding reaction both 

 ends take part, the tail being chiefly instrumental in causing the 

 anmial to recoil from the stimulating object. Accessory move- 

 ments may occur after food-taking; the larva sometimes shakes 

 its prey after capture. 



Other Movements. — The other class of movements referred to 

 as convulsive or wriggling may also be made to include those 

 directed at the animal's own body, which appear like cleaning 

 movements. In wriggling the ends contract oppositely forming 

 an S, and repeating this a number of times, with twisting on the 

 long axis. These wrigglings sometimes occur after a longer period 

 of quiescence than usual. They appear like ebullitions of super- 

 abundant energy. 



REACTIONS OF THE LARVAE— APPLICATION OF THE " LOCAL 

 action" THEORY OF TROPISMS. 



Locomotion is of the same form w^hether due to external stimu- 

 lation, or spontaneous. It may therefore be positive, negative 

 or indifferent with reference to the environment and have the 

 same form in each case. Food-taking, as was seen, on account of 

 the difference in form should be classed separately. According 

 to the theory of tropisms, a mode of orientation was formulated 

 for all animals. As applied to the earthworm, the theory is given 

 as follows in Davenport's summary of Loeb's views. It is very 

 true that an explanation which is applicable to the earthworm is 

 not invalidated because of its partial or complete failure to apply 



