176 DARWINISM AND THE PROBLEMS OF LIFE 



do it much injury on account of its smallness. Its 

 organs are gradually developed, and when it is quite 

 ready it releases itself by vigorous movements from 

 the skin, and follows the adult life of its species at 

 the bottom of the water. It is a remarkable and 

 interesting correlation of two very different animals. 



Other fishes meet the danger of destruction by 

 producing enormous masses of eggs. In some these 

 eggs are poisonous, as in the case of the pike and 

 the barbel ; in the latter case, in fact, the whole fish 

 is poisonous at the spawning season. It is often 

 compared to the pig, as it always remains at spots 

 where sewage runs into the water. It is even believed 

 that human corpses are its greatest delicacy ; a large 

 number of barbel were found on the bodies of the 

 slain in the Danube in 1683, at the siege of Vienna 

 by the Turks, while none were seen on the bodies of 

 animals. Barbel are sometimes taken from the inside 

 of dead bodies. 



Fishes know their enemies well. It has been 

 observed, in fact, that they have a memory ; that 

 fishes at which a diving - bird was set first circled 

 round it with curiosity, but when it had caught several 

 of them, hid themselves, and were very cautious 

 afterwards. They also learn to recognise the servant 

 that brings their food ; but the statement that they 

 gather for food when the bell rings rests on unsafe 

 observations. It is very probable that they have no 

 sense of hearing. Their ear serves only as a sense 

 of equilibrium ; fishes from which the ears have been 

 removed cannot keep themselves upright in the water, 



