THE TROPICAL FOREST 119 



and it can also leap and skip over the mud. The eyes 

 are very prominent, are furnished with distinct eyelids, 

 and are protrusible. The fish, which are very tadpole- 

 Mke in appearance, feed upon insects. 



In India and the south-east of Asia generally, another 

 fish is found which can live on land, and voluntarily 

 leaves the water to do so. This is the chmbing perch 

 {Andbas scandens), a freshwater form which travels 

 long distances over land by hitching its pectoral fins 

 round plants. The fish is also stated to be able to 

 climb trees. It has a special accessory breathing organ, 

 which enables it to breathe air when out of the water. 



In regard to the invertebrates, a special feature of 

 the tropical forests is the great wealth of insects. That 

 this must be so wiU be clear when we reflect that 

 some of the forest-dweUing primates, the insectivores, 

 many of the marsupials, some carnivores, the eden- 

 tates, many reptiles and amphibians and so on, eat 

 insects, either solely or in combination with other types 

 of food. Further, the equal temperature allows the 

 insects to go on breeding all the year round, and thus 

 permits a great wealth of individuals to occur, while 

 the special conditions favour a great wealth of genera 

 and species. Apart from the size and beauty of the 

 tropical butterflies, the most impressive of the insects 

 are first the flies, which are often blood-suckers, and 

 then may, as in the case of mosquitoes and tsetse flies, 

 serve as transmittors of the tropical diseases most fatal 

 to man and beast, and second the ants, some of which 

 are extraordinarily destructive to plant life, while 

 others from their numbers and ferocity are the enemies 

 of aJl other animals. The driver ants of West Africa, 

 which are wandering forms, are stated to devour every 

 living creature in their path which cannot make its 



