xvi. TffORNIES AND TINKERS. 233 



fish disported themselves. In fact so much did he drive 

 and harass her, that I removed her out of the way of her 

 tempting progeny, and of a morose husband who would 

 not let her enjoy the children she had brought into the 

 world. After that he did not take much notice of his 

 little flock ; and I have never seen him bring back tenderly 

 in his mouth those that had strayed too far from home 

 a fact that is, however, vouched for by more than one 

 observer. 



I have before me some of these minute Thornies, martyrs 

 to science, mounted in Canada balsam. I will choose one 

 about ten days old for description. Under low powers of 

 the microscope, and especially by reflected light with a 

 good binocular, the young stickleback is a very beautiful 

 object. The head is short and blunt, and the eye rela- 

 tively enormous, a central black spot, the pupil, being 

 surrounded by a ring of iridescent blue. A little behind 

 the eye may be seen two circular spots, delicately lined 

 with fine radial striations, where the bones of the gill-cover 

 are beginning to ossify. Further back is seen a large 

 hollow clear space within the body ; this is the swim- 

 bladder. The alimentary canal can be easily traced ; and 

 there is evidence in the individual before me of a recent 

 hearty meal of water-fleas. The dorsal and anal fins are 

 represented by a clear, straight fringe above and below the 

 body, in which, in stained specimens, the commencing fin- 

 rays have taken the colour a little more decidedly than 

 the rest. 



But the most remarkable feature about this little' 

 Thornie is his tail, which, instead of resembling that of 

 his father and mother, looks more like that of a dog-fish. 

 In the full-grown stickleback the tail is symmetrical, like 

 that of a herring or cod-fish. But in the Thornie a few 

 days old it is not at all symmetrical. The upper portion 



