1910] BurrilJ, How Sanguinary Ants Changs Direction. 131 



straighten the trail was here continually in conflict with that of the 

 ants ahead who curved the trail on purpose, seemingly, to avoid 

 the wet grass region and choose the easier traveling on the tar. 



In the present state of our insect psychology, we cannot feel 

 very well satisfied with any reasoned explanation of insect activity, 

 since our anthropomorphic viewpoint is continually upsetting sane 

 conclusions. Forel warns us "When we judge of the sensations 

 of animals, we must assume nothing of their quality, properly 

 so-called;" and in his general platform of principles for judging 

 insect behavior 5 he says "We can only judge of the animals' sense 

 of smell by the reactions which occur when it runs away from or 

 searches for what it has just perceived." We see then, how slight 

 is the objective criterion on which to build our hypothesis of 

 scented trails, "hi the case of the sense of touch and its varieties, 

 following upon immediate contact," etc. It should appear, then, 

 we are, equally, only able to judge of the reactions of the animal 

 that the chief desideratum in the study of ants on the trail is 

 the exacting geometrical and mathematical record of habits ob- 

 served, from which, as methods of observation are refined, we 

 may hope to organise some more exact science of the subject. 



Public Museum, Milwaukee, Wis. 



June 16, 1900. 



5) A. Forel. The Senses of Insects. l'JOS trans, p. 2. Methuen & Co., 

 London. 



