56 Instinct and Intelligence 



ascending orders of animals would thus be 

 something akin to a deeper and deeper impres- 

 sion of light on a substance which, being 

 organised, possesses a special aptitude for 

 receiving and rendering it hereditary. 1 Pro- 

 fessor F. Soddy, when referring to this subject, 

 observes that the human eye has become 

 adapted through long ages to the peculiarities 

 of the sun's light, so as to make the most of 

 that wave-length of which there is the most. 2 

 In the following chapter we hope to show that 

 in the Star-fish the connection between its visual 

 sensory organs, their corresponding nervous 

 system, and the instinctive behaviour of these 

 animals is even more conclusive than that which 

 exists in the case of their allies the Medusoids. 



1 Creative Evolution, by H. Bergson, p. 73. 



2 Matter and Energy, by F. Soddy, p. 193. 



