222 THE ZOOLOGIST. 



if we remember where these eggs are deposited and what an 

 amount of pressure they may have to undergo. Young Salmon 

 are hatched from eggs deposited in rivers, such as the Severn — 

 not near its mouth, where the tide or the current would be too 

 strong for the baby-fish to live in, but in small and often moun- 

 tainous streams, where the water is pure and shallow, having a 

 gravelly bed which permits the redd, or nest, to be constructed, 

 while deep pools in the vicinity allow the breeding-fishes to retire 

 into them for rest. 



The places selected by fishes for depositing their eggs vary in 

 different families. Thus the ova of the Cod floats on the surface 

 of the sea until the young come forth ; that of the Herring sinks 

 to the bottom, where, bj r means of a glutinous substance, it 

 becomes attached to sea-weeds, rocks, or other objects. One 

 form of Sea- sucker (Lepadogaster) attaches its eggs to the inside 

 of an old shell, as a butterfly does to a leaf. The Perch in our 

 fresh waters have stringy ova, which is made fast by one end to 

 some stationary object, as grass or timber. That of some species 

 of Carp sinks into the mud of ponds ; while a few of the 

 tropical scaleless Siluroids that reside along the coasts have this 

 remarkable peculiarity, that the male carries the eggs about in 

 his mouth until the young are hatched. Our Common Stickle- 

 back forms a veritable nest, which is attached to a water-plant, 

 and this nest has one hole by which the fish enters and another 

 on the opposite side by which it emei'ges. 



But none of the foregoing plans are followed by the Salmon, 

 which ascends our rivers to a suitable spot, and in the gravel at 

 the bottom of the stream constructs its redd or nest, which work 

 seems to be the occupation of the female. She lies on one side, 

 and, by moving her tail rapidly from one side to the other, fans 

 up the gravel until she rapidly sinks into a kind of trough, the 

 male remaining near ready to give battle to any intruder, for 

 which purpose his lower jaw is furnished at this period with an 

 offensive weapon in the shape of a cartilaginous, hook-like process. 

 The female (waited upon by the male) now deposits her eggs in 

 the trough she has made in the gravel, and these are subsequently 

 covered to some feet in depth, the whole forming a redd. She 

 now falls back into one of the deep pools until she has acquired 

 sufficient strength to deposit more eggs. During this period 

 Salmon (like Shad and many other fishes) are indisposed to feed, 



