152 THE STORY OF FISH LIFE. 



the mud and set free the captives, who were soon 

 swimming about as if in their native rivers. 

 Some of these fish were kept alive for many 

 months. 



The Indian serpent-head (OpJiiocephalus) like- 

 wise passes prolonged seasons of drought en- 

 closed in mud, emerging therefrom only after 

 the rains have filled the bed of the stream. 



The climbing-perch (Anabas) of Ceylon also 

 withdraws to a mud retreat, and is habitually 

 unearthed with the shovel by natives. 



A trout-like species of fish (Neochanna) of New 

 Zealand is so far known only by specimens which 

 have been obtained from mud-burrows at a dis- 

 tance from water. These burrows are excavated 

 by the fish, but how, or under what conditions, 

 appears yet to be a mystery ! 



CHAPTER XII. 



TRANSFORMATIONS 



THE stock-in-trade with which fishes start in life 

 is a comparatively limited one, being no more, 

 in fact, than is sufficient to complete the outfit 

 necessary to meet immediate needs. Evolution, 

 progressive or otherwise, is possible only by 

 modifications of, and additions to, the original 

 structures represented in the person of the founder 

 of the house. Other chapters in this little book 

 bear witness to the magnitude of the changes which 

 have taken place during the development of the 



