CHAPTER XIX. 



SUB-AQUATIC NESTS. VERTEBRATES. 



Fishes as architects — The Sticklebacks and their general habits — The Fresh - 

 Water Sticklebacks — A jealons proprietor — Punishment of trespassers — 

 Form and materials of the nest — Use of the nest — Cannibalistic propensities — 

 The Fifteen-Spined Stickleback, and its form — Its curious nest— Mr. 

 Couch's description of a nest in a rope's end — Fishes of Guiana — The Hassar 

 or Hardback, and its place in zoology — Nest of the Hassar — Parental watch- 

 fulness — Singular position of the nest—Habits of the Hassar. 



As a rule, Fishes display but little architectural genius, their 

 anatomical construction debarring them from raising any but 

 the simplest edifice. A fish has but one tool, its mouth, and 

 even this instrument is of very limited capacity. Still, although 

 the nest which a fish can make is necessarily of a slight and 

 rude character, there are some members of that class which 

 construct homes which deserve the name. 



The best instances of architecture among the Fishes are those 

 ■which are produced by the Sticklebacks {Gasterosteus), those 

 well-known little beings whose spiny bodies, brilliant colours, 

 and dashing courage make them such favourites with all who 

 study nature. There are several species of British Sticklebacks, 

 but as the fresh-water species all make their nests in a very 

 similar manner, there will be no need of describing each species 

 separately. 



These fishes make their nests of the delicate vegetation that 

 is found in fresh water, and wiU carry materials from some little 

 distance in order to complete the home. They do not, however, 

 range to any great extent, because they would intrude upon the 

 preserve of some other fish, and be ruthlessly driven away. 



When the male Stickleback has fixed upon a spot for his 

 nest, he seems to e.nnsider a certain area around as his own 



