THE METHOD OF HOMING PIGEONS. 



761 



animals, by the processes going on in their bodies, must have 

 some notion of time. This would give the " how long " element 

 in the problem. The " how fast " might be given by such an in- 



STATE 

 CAPITOL 



Fig. 2. 

 flight of six pigeons, covered cagB. 



strument as we find in the otoliths resting on the sensory hairs of 

 the maculcB acousticcE; these hairs bending under the weight more 

 or less, according to rate of movement. The " which way " could 



