282 LOWER VERTEBRATES. 



" Tlie site is generally amongst the stems of aquatic plants, where the water al- 

 ways flows, but not too swiftly. He first begins by carrying small bits of green ma- 

 terial, which he nips off the stalks, and tugs from out the bottom and sides of the 

 banks ; these he attaches by some glutinous material, that he clearly has the power of 

 secreting, to the different stems destined as pillars for his building. During this ope- 

 ration he swims against the work already done, splashes about, and seems to test its 

 durability and strength ; rubs himself against the tiny kind of platform, scrapes the 

 slimy mucus from his sides to mi.x with and act as mortar for his vegetable bricks. 

 Then he thrusts his nose into the sand at the bottom, and, bringing a mouthful, scatters 

 it over the foundation ; this is repeated until enough has been thrown on to weight 

 the slender fabric down, and give it substance and stability. Then more twists, 

 turns, and splashings to test the firm adherence of all the materials that are intended 

 to constitute the foundation of the house that has yet to be erected on it. The nest, 

 or nursery, when completed, is a hollow, somewliat rounded, barrel-shaped structure, 

 worked together much in the same way as the platform fastened to the water-plants ; 

 the whole firmly glued together by the viscous secretion scraped from off the body. 

 The inside is made as smooth as possible by a kind of plastering system ; the little 

 architect continually goes in, then, turning round and round, works the mucus from his 

 body on to the inner sides of the nest, where it hardens like tough varnish. There 

 are two apertures, smooth and symmetrical as the hole leading into a wren's nest, and 

 not unlike it. 



"All this laborious work is done entirely by the male fish, and when completed he 

 goes a-wooing. Watch him as he swims towards a group of the fair sex, enjoying 

 themselves amidst the water-plants, arrayed in his best and brightest livery, all smiles 

 and amiability ; steadily, and in the most approved style of stickleback love-making, 

 this young and wealthy bachelor approaches the object of his affections, most likeh' 

 tells her all about his house and its comforts, hints delicately at his readiness and abil- 

 ity to defend her children against every enemy, vows unfailing fidelity, and, in lover- 

 fashion, promises as much in a few minutes as would take a lifetime to fulfil. Of 

 course she listens to his suit ; personal beauty, indomitable courage, backed by the 

 substantial recommendations of a house ready-built and fitted for immediate occupa- 

 tion, are gifts not to be lightly regarded. 



" Throwing herself on her side, the captive lady shows her appreciation, and by 

 sundry queer contortions declares herself his true and devoted spouse. Then the 

 twain return to the nest, into which the female at once betakes herself, and therein 

 deposits her eggs, emerging, when the operation is completed, by the opposite hole. 

 During the time she is in the nest (about six minutes) the male swims round and 

 round, butts and rubs his nose against it, and altogether appears to be in a state of 

 defiant excitement. On the female leaving, he immediately enters, deposits the milt 

 on the eggs, taking his departure through the back door. So far, his conduct is 

 strictly pure ; but I am afraid morality in stickleback society is of rather a lax order. 

 No sooner has this lady, his first love, taken her departure, than he at once seeks 

 another, introduces her as he did the first, and so on, wife after wife, until the nest is 

 filled with eggs, layer upon layer, milt being carefully deposited betwixt each stratum 

 of ova. As it is necessary there should be two holes, by which ingress and egress can 

 be readily accomplished, so it is equally essential in another point of view. To fer- 

 tilize fish-eggs, running water is the first necessity ; and, as the holes are invariably 

 jilaced in the direction of the current, a steady stream of water is thus dii-ected over them." 



