THE STICKLEBACK. 57 



plantain grow and forget-me-nots fringe the banks. The runlet is clear 

 and moderately rapid, the Boil at the bottom is alternate shingles and 

 white sand, with here and there a dark patch of mud, and here and 

 there a huge stone, around which the water circles, forming tiny eddies 

 and miniature whirlpools. Near to one of these we will quietly seat 

 ourselves on the soft bank and peer into the water carefully. The 

 planorbia water snail is slowly peregrinating the leaf of a large alisma or 

 water plantain, and near the stem of the latter is poised a fine 

 Stickleback, with gorgeous silver green sides and lustrous eyes, all 

 accoutred with spines and spikes, expectantly gazing at a group of smaller 

 ones a little lower down, whom he evidently has but recently put to flight. 

 Slowly they again seem bent on disturbing him in his dignified repose and 

 swim shyly up stream approaching his lordship. As they near him, with 

 a sudden dash he is amongst them, and they are scattered far and wide, 

 one little mite being ripped open by the powerful spines. The victor 

 returns again with satisfaction to his former station ; and now watch his 

 further proceedings. First he swims leisurely around the stem of plantain 

 as if debating what course to pursue. Probably he is preparing a mental 

 estimate, or, being his own architect, is constructing a plan, for he is 

 about to build as elaborate a nest as ever the Long-pod constructed amid 

 the close foliage of the box tree. After a while he begins operation by 

 tugging water weeds, conferva, and various other suitable debris to the 

 selected site, and this accomplished, he solidifies the foundations by 

 strewing a few good mouthfuls of sand upon them. Nature has not left 

 him unprovided with cement, and in proof of this, the next step is to glue 

 the materials together, which is accomplished by the little creature 

 drawing its body over the structure and depositing a mucus, which seems 

 to harden in the water. This is not the only means taken for the 

 stability of the edifice. After the cement has been applied the fish may be 

 seen driving, by means of its powerful fins, currents of water against 

 it, which is evidently for the purpose of finding if a weak place exists. 

 Should a grain of sand or piece of weed become displaced, it is immedi- 

 ately restored to its position and firmly cemented. Sometimes, to try 

 the strength of the structure still more vigorously, the fish hurls itself 

 against it, and this not once only, but repeatedly. 



To aveid misapprehension, I may state that the building processes de- 

 tailed above occupy usually some days. I have compressed the period 

 in describing them for the convenience of the reader. 



The foundations once sure and complete, the next operation is to collect 

 materials and build the walls of the nest. The object of the fish is to 

 build a barrel-shaped structure, as smooth as possible inside. For this 

 purpose the process of selection and rejection sometimes goes on for 



