316 The Animal Mind 



suggestive of the " distraction of attention" in a human 

 being (335). Holmes (337) also observed that the fiddler 

 crab, although it ordinarily moves towards the light, would 

 run away from a moving light, fear overcoming positive 

 phototropism. Roubaud, in a study of the behavior of 

 some species of flies that live on the seashore, feeding on 

 dead fish and the like, says that they will abandon the 

 "head on" position which they regularly assume toward 

 the wind, if attracted by the odor of food (646). 



Wherever we find that one class of stimuli regularly 

 yields to another if the two act together, it is safe to assume 

 that the prepotent stimulus is more important to the organ- 

 ism's welfare than the vanquished one. And while we can- 

 not without more ado call such cases of the interference of 

 stimuli as are found in very simple animals cases of atten- 

 tion, and ascribe to their psychic accompaniment all the 

 characteristics of attention as a feature of our own expe- 

 rience, yet we may assert that they have in common with 

 attention the significance of being a device to secure reaction 

 to the most vitally important of several stimuli acting at once 

 upon the organism, 



82. Methods of securing Prepotency of vitally Important 



Stimuli 



An inanimate object acted upon by several forces at once 

 is determined in its motion by their relative intensity. Con- 

 ceivably, an extremely simple form of animal life, when 

 subjected to two- stimulations acting together, would also 

 respond in a way answering precisely to the relative strength 

 of the two. It is easy to see what would be the disadvantage 

 of such a state of affairs for the animal. The weaker of 

 the two stimuli might be of far greater significance for 



