CONDITIONS OF LIFE 301 



fish is skilful enough to enter the anemone without touching its 

 tentacles or even the sides of its stomach. The case is so extra- 

 ordinary that if we did not know it to be true it would seem 

 almost as incredible as the ancient fable of the salamander living 

 in fire. It is not, however, the only case of its kind, for a similar 

 companionship occurs between an allied species of anemone and 

 a prawn, the latter having a brilliant coloration similar to that 

 of the fish. 



Glyphidodon anabantoides, another of the Pomacentridae, 

 protects itself by hiding among the branches of corals. Day 

 found at the Andaman Islands that some of these fish could 

 always be captured by obtaining pieces of coral from the bottom 

 of the water : the fish remained closely packed in the crevices 

 of the coral even when it was broken off and brought to the 

 surface by the native divers ; fear did not cause them to leave 

 their retreats, but only to penetrate more deeply into them. 



Fish are infested with numerous parasites of various kinds, 

 both internal and external, but it rarely happens that non-para- 

 sitic fixed growths, whether of animal or vegetable nature, are 

 found on their bodies. Hydroid zoophytes and sea-anemones 

 are frequently found growing on the shells of bivalve molluscs, 

 or on the shells inhabited by hermit-crabs, and in several such 

 cases a particular species of hermit-crab is invariably associated 

 with a particular species of hydroid or anemone. A single case 

 of a similar association between a fish and a hydroid zoophyte 

 has been described by Lieut-Col. Alcock in his Naturalist 

 in Indian Seas, in which he gives an account of the results of 

 the scientific investigations made on board the Investigator in 

 the Bay of Bengal. The fish in question, Minous inermis, 

 belongs to the Scorpaenidae, most of which are characterised by 

 large heads furnished with formidable spines. Most of the 

 Scorpaenidae are of inactive habits and live on the bottom or 

 among rocks, and many of the species afford striking examples 

 of what is called " protective resemblance " ; they have inconspicu- 

 ous colours in irregular blotches harmonising with the rocks, 

 weeds, stones, etc., and often the skin is abundantly furnished with 

 loose membranous flaps or filaments, which by waving about in 

 the water make the appearance of the fish still more deceptive. 

 In Minous inermis, which is only a few inches long, and lives on 

 the east coast of India, the skin is actually covered with living 



