ANIMAL BEHAVIOUR 197 



that they bring about an end. How the conative bow of 

 the starfish was bent towards that end and kept towards 

 that end, who shall tell us, but that we have here to do with 

 behaviour seems undeniable. It appears to us to be an 

 important fact that ganglionless animals show a trial-and- 

 error method, a selection of the responses that put things 

 right, and for a short time, at least, a profiting by experience. 

 We cannot call this intelligent behaviour, but it is objec- 

 tively the counterpart of intelligent behaviour. 



This stage in the evolution of behaviour may be said to 

 mark one of the great events in the history of life. As the 

 organism became more differentiated it was open to a larger 

 number of stimuli ; as it gained a foothold in particular 

 situations " the door to choice was unlocked " ; as experience 

 began to be garnered it became possible for an internal im- 

 pulse to control the natural reaction to a stimulus. This 

 was the dawn of freedom. 



8. Instinctive Behaviour. 



When a spider makes a web or the bees a honeycomb, 

 when a digger-wasp paralyses insects and stores them in its 

 burrow as provender for its offspring, when a male stickle- 

 back builds a nest, when a young moorhen swims deftly the 

 first time it touches the water, we have to deal with instinc- 

 tive behaviour. It reaches its climax and its purest expres- 

 sion in Arthropods, such as ants, bees, and wasps; in birds 

 and mammals it is more likely to occur in co-operation with 

 intelligence. 



There seems indeed to be a sharp contrast between what 

 Sir Ray Lankester calls the big brain type, which reaches its 

 finest development in birds and mammals, and the little brain 

 type, the climax of which is in ants, bees, and wasps. The 



