1 1 o Instinct and Intelligence 



haviour of the mud-fishes of Guiana, possess- 

 ing as they do a somewhat higher type of brain 

 than that of the cartilaginous fishes; it is 

 interesting to find the instinctive behaviour of 

 these animals is also of a superior character 

 to that displayed by any of the lower orders of 

 the same class of beings. For instance, the 

 mud-fish of South America is in the habit of 

 constructing a nest in the banks of the stream 

 it inhabits, which it makes from grass and the 

 leaves of water-plants. These it binds together 

 so as to form a secure place in which the female 

 can deposit her eggs. The male fish keeps 

 watch over the eggs, and the young fish until 

 they take to the water and begin an independent 

 existence. These fish travel for a considerable 

 distance over the land dividing one stream 

 from another ; during the dry season they bury 

 themselves in the bed of a stream, and remain 

 there until the return of the rains, which 

 soften the earth in which they have slept 

 and thus release them from their temporary 

 grave. 



The small animal with which most of us are 

 familiar, commonly known as the stickleback, 



