Nest-Building Fishes. 167 



Marked differences in details of structure, configuration and 

 surroundings are apparent, which prove that these creatures 

 are controlled by reason, rather than instinct, in the elabo- 

 ration of their homes. That they have some means of com- 

 municating their desires to each other cannot be doubted. 

 When the male has laid hold of a stem, a pebble or a stick 

 that completely baffles all effort at removal, his mate seems 

 summoned to his assistance, and the united strength of the 

 pair accomplishes the object to be gained. There is ever 

 noticeable in whatever the sexes undertake some concert of 

 action which would put to shame the boasted intelligence of 

 man himself. The Sun-fishes, as has been said, nest in com- 

 panies. When the combined effort of two individuals is un- 

 able to expel an invader, the entire community, a*s by a single 

 mighty impulse, rises up against the foe. There is evidence 

 of some form of society, even though simple in its organiza- 

 tion, where individual members league themselves together 

 for mutual protection and defence. Other examples might 

 be cited to give the reader a common-sense estimate of the 

 comparatively high order of intelligence that characterizes 

 the actions of many of our fishes. 



