THE THEORY OF TITTLEBATS. 833 



arranging the whole to his mind, and again and again adjusting it 

 until he was satisfied ; after which he hung or hovered over the sur- 

 face of the nest, his head close to the orifice, the body inclined upward 

 at an angle of about 45, fanning it with the pectoral fins, aided by 

 a side motion of the tail. This curious manoeuvre was apparently for 

 the purpose of ventilating the spawn ; at least by this means a current 

 of water was made to set in toward the nest, as was evident by the 

 agitation of particles of matter attached to it. This fanning, or ven- 

 tilation, was frequently repeated every day till the young were hatched ; 

 and sometimes the little fellow would dive head foremost into his nurs- 

 ery and bring out a mouthful of sand, which he would carry to some 

 distance and discharge with a puff. At the end of a month the young 

 ones were first perceived. The nest was built on the 28d of April ; 

 the young appeared on the 21st of May." 



After the young are actually hatched, the fond parent only redoub- 

 les his delicate attentions. He never leaves the precincts of home 

 by day or night ; and he guards the nest with the utmost pertinacity, 

 allowing no stray intruder from any side to approach it. If a greedy 

 water-beetle or other enemy comes near the young, this exemplary 

 father runs full tilt at him with his armed spines, pounces upon him 

 broadside, and unceremoniously shoves or tumbles him over. If you 

 try to disturb him in an aquarium with a stick or pencil, he will charge 

 at it smartly, and strike it so hard that the blow can be distinctly felt 

 by the hand that holds it. Among the enemies he has to repel on 

 such occasions, I regret to say (for the honor of maternity I would 

 fain conceal the fact), are the mothers themselves of his little charges, 

 who wish to emulate Saturn and the common rabbit by making a din- 

 ner off their own flesh and blood. " For a whole month," says Dr. 

 Gunther, " he watches over his treasure, defending it stoutly against 

 all invaders, and especially against his own wives, who have a great 

 desire to get at the eggs." Those unnatural parents, indeed, make 

 such a dead set upon their young and the devoted father who guards 

 them, that, as Mr. Darwin cynically observes, "it would be no small 

 relief to him if after depositing their eggs they were immediately de- 

 voured by some enemy, for he is forced incessantly to drive them from 

 the nest." Let us trust that the wedded stickleback himself never 

 indulges in such uxoricidal fancies. 



The fry, when hatched, are at first so very minute and transparent 

 that you can with difficulty perceive them in the water of an aquarium, 

 and even so only by the gentle fluttering motion of their wee fins. 

 Their good papa continues, however, to perform the duties of a nurse 

 for them with profound vigilance, confining them at first to the meshes 

 of the nest, and, when they stray too far, gently leading them back 

 with unremitting kindness to the path of duty. By degrees, as their 

 knowledge of the world increases, he wisely allows them to indulge in 

 greater excursions, and hollows out for them a small basin in the sand 

 vol. xxxi. 53 



