48 



A HISTORY OF FISHES 



alive by the Chinese to San Francisco and to Hawaii, where 

 they are now naturaHsed and known as "China-fishes." They 

 are able to survive prolonged drought, burying themselves in 

 the mud and remaining in a torpid state during hot, dry weather. 

 The various species differ in the extent to which they have 

 developed the air-breathing habit, as well as in their power of 

 living out of water. The accessory respiratory organs are of a 

 much simpler character than those of the CUmbing Perch, 

 consisting of a pair of simple cavities Hned with a thickened 

 and puckered membrane supplied with blood-vessels, and do 

 not contain any special structures. These lung-like reservoirs 



Fig. 21. FISHES THAT CAN LIVE OUT OF WATER. 



A. Snake-head (Ophiocephalus striatus), X ^ ; b. Cuchia (Amphipnous cuchia), X }. 



are not developments of the branchial chamber, but are pouches 

 of the pharynx. 



Other fishes provided with accessory breathing organs are 

 certain Cat-fishes of the rivers and swamps of Africa and Asia, 

 and the famous Cuchia (Amphipnous) of India and Burma, a 

 member of the group of Symbranchoids (Fig. 2ib). In one of 

 these Cat-fishes (Clarias) the organs take the form of elaborate 

 tree-like structures, growing from the upper ends of the gill- 

 arches and contained in a pair of air-chambers situated above 

 the gills (Fig. 20c). Another form {Saccobranchus) has the 

 organs of a simpler nature, but the air-chambers bear a marked 

 resemblance to lungs, extending backwards as far as the tail 

 as long tubular sacs growing out from the branchial cavity, 



