THE FIFTEEN-SPINED STICKLEBACK. 



227 



Fifteen-spined Stickleback, made in the end of an old rope : " A singular instance of 

 constructive skill and patience in the formation of its nest, which occurred within my 

 knowledge, is deserving of remembrance. The situation selected was the loose end of 

 a rope, from which the separated strands hung out about a yard from the surface, over 

 a depth of four or five fathoms, and to which the materials could only have been brought, 

 of course, in the mouth of the fish, from the distance of about thirty feet. 



They were formed of the usual aggregation of the finer sorts of green and red sea- 

 weed, but they were so matted together in the hollow formed by the untwisted strands 

 of the rope, that the mass constituted an oblong ball of nearly the size of the fist, in 

 which had been deposited the scattered assemblages of spawn, and which was bound 

 into shape with the thread of animal substance already described, and which was passed 

 through and through in various directions, while the rope itself formed an outside 

 covering to the whole. 



JAPANASB SINaLETHORN.-/HoflOcenfrfr J&poalcus. 



We can scarcely suppose that such a nest can have been the work of more than a 

 couple of fishes, but the grains of spawn had grown to almost the size of radish-seeds, 

 and in collective bulk seemed greatly disproportionate to the size of the parent, and 

 only to be explained by the well-known fact, that the ova of fishes generally obtains 

 an increase of bulk by the absorption of water after exclusion ; which fluid may be 

 supposed to exert considerable influence on the further development of the young. 

 The embryo of this fish, as is believed to be the case with many others, is not found to 

 bear a close resemblance to the parent, and in fact may be said to pass through a 

 decided metamorphosis in the course of its final development." 



The jaws of this species are much elongated, and the under jaw protrudes well beyond 

 the upper. Along the back runs a row of fifteen spines, short, sharp, slightly hooked 

 backwards, and each with a very slight membrane. Along the lateral line runs a series of 

 keeled scales, and .on the abdomen are two bony plates, bearing on their inner edges 

 two sharp spines of unequal length. If the body be severed at the centre, the line of 

 section will be nearly a pentagon. The upper part of the head, body, and tail is olive- 

 green, taking a golden tint on the sides. The rest of the body is silvery white. The 

 length of this fish varies from five to seven inches. 



