1 66 Life and Immortality, 



thread is wound round and round the nest in a horizontal 

 direction, and when freshly spun is found to consist of six 

 or eight very thin transparent fibres, which have alternated 

 tapering ends where they are broken off. Very soon after 

 the thread is spun, particles of dirt adhere to it, and render it 

 difficult to interpret its character. The nest measures one- 

 half of an inch in height, and three-eighths in diameter. 



The time occupied in collecting materials and constructing 

 the nest ii about four hours, and when all is ready the male 

 starts out to seek a female, and, having found her, conducts 

 her with many polite attentions to the prepared home. The 

 eggs being deposited, the male establishes himself as a guardian 

 of the precious treasures, not even suffering the female to 

 approach it again. Every fish that comes near, no matter 

 how large, is furiously assailed. He gives battle valiantly, 

 striking at their eyes and seizing their fins in his mouth. 

 His sharp dorsal and ventral spines are very effective weapons 

 in his defence. Constant watchfulness upon the part of the 

 male is needed, for, if he go away for only a few moments, 

 the sticklebacks and other fish lurking in the vicinity rush 

 in and devour the eggs in an instant. A whole month he is 

 occupied in providing for the safety of his offspring. About 

 the tenth day he employs himself in tearing down the nest 

 and carrying the material to some little distance. The fry 

 may now be observed in motion. And these the male con- 

 tinually nurses, suffering no encroachment, and if the young 

 brood show a tendency to stray beyond bounds, they are 

 driven back within their precincts, until they are strong 

 enough to provide for their own living, when both old and 

 young disappear together. 



But nothing in the lives of all these little nest-builders is 

 more interesting than the intelligence they display and the 

 facility with which they adapt themselves to circumstances. 

 They seem to be able to grasp almost instantly the conditions 

 of the environment, and to employ a wise discrimination in 

 suiting them to their wants. Hardly two nests are alike. 



