CH. II] 



THE CRAYFISH 



63 



latter upon the sensory setae. A similar diminution would 

 be, and on all previous occasions within the experience of 

 the animal has been, effected by the downward inclination 

 of the right side of the animal's body. Hence the sensation 



Fig. 10. 



produced is that of slipping downwards to the right. Ac- 

 cordingly the creature inclines itself towards the right as 

 though walking on a surface sloping downwards in that 

 direction (Fig. 10). Again, if, as in Fig. 11, the magnet 



M 



Fig. 11. 



