238 



ZOOLOGY 



The sticklebacks are small, elongated fishes, having an 

 extremely slender tail and a large mouth. The dorsal fin 

 is preceded by two or more large isolated spines. The 

 fishes live in either fresh or brackish water. In some of 



FIG. 220. Gastsrosteus bispinoxns, the two-spined stickleback. Above, nest 

 with eggs, and male entering. Below, male depositing its mil on the eggs. 



Figs. 219 and 220 are reproductions of water-color paintings in the Museum 

 of Comparative Zoology at Harvard College. 



the species the male builds an elaborate nest from bits of 

 aquatic plants, firmly united by a special mucilaginous 

 secretion. The nest, which is built among the plants of 

 the stream, consists of a short cylinder, through the hori- 



