NUMBER OF EGGS AND IP PROTECTION IS NECESSARY. lxiii 



been observed in an aquarium to roll the gravid female like a cask along 

 the bottom of the tank, and to continue this operation without relaxation 

 for a day or two until the wearied female has extruded her ova. The 

 female river lamprey is said to be assisted by the male twisting himself 

 around her, and so expressing the ova and milt, the suctorial mouths of 

 both parents being at this time attached to a stone or other suitable 

 stationary object. While it does not appear unlikely that the female salmon 

 or trout when forming the redd or nest by lateral strokes of the side and 

 tail portion of the body is by such active exertion assisting in ridding 

 herself of her eggs. It has been asserted that among these latter fish 

 when the eggs are ripe there is no power to prevent their escape, but at 

 Howietoun it is found that if the parents are placed in a wooden tank, 

 having smooth sides and bottom, and through which a stream flows, ovula- 

 tion may be deferred days, and even weeks. 



The number of eggs deposited by teleostean fish is, as already remarked, 

 exceedingly vained ; thus, a perch of 1^ lb. contained 280,000 ova, one of 

 3 lb. 2 oz., 155,620; a ruff, of 4| oz., 205,000; an angler, of. 1 lb. 13 oz., 

 1,427,344; a mackerel, 18 oz., 546,681; lump-sucker, 6^ lb. weight, 

 207,700, at 9 lb. 8 oz., 155,000 ; cod, at 11| lb., 1,800,000, but upwards of 

 3,000,000 have been taken from one; haddock, 21 lb., 169,050, at 9 T 9 ^ lb., 

 1,839,581; coal-fish, at 21 lb., 8,260,000; pollack, 12 lb., 4,200,000; 

 hake, the roe of which weighed 15| oz., 1,500,000 ; ling, 20 lb., 19,985,400, 

 one of 100 lb., 160,000,000; burbolt, 128,000; halibut, 3,500,000; turbot, 

 5 lb. 9 oz., 14,311,200; plaice, 4 lb. 15 oz., 144,600; flounder, 24* oz., 

 1,357,400, at 6| oz., 351,026, at 3 oz., 225,568, at 21 oz., 133,407; sole, 

 1 lb., 134,000 ; salmon, about 900 to every 1 lb. weight, but may exceed 

 this, one of 20 lb. contained 27,850 ; trout, about 800 to every 1 lb. weight; 

 charr, | lb., 1,230; pollan, llf oz., 6,156; smelt, 2 oz., 28,278, and in a 

 second the same size, 36,652 ; pike, 35 lb., 43,000, 32 lb., 595,200, 28 lb., 

 292,320, a second 700,000, 24 lb., 224,640; carp, at 9 lb., 600,000, 

 16| lb., 2,059,750, 21| lb., 1,310,750; barbel, 7,000 to 8,000 ova; roach, 

 28 oz., 480 ; tench, 4 lb., 297,000 ; bream, 130,000 ; white bream, 108,000 ; 

 herring, 10,000 to 30,000 ; pilchard, 60,000 ; conger, 15| lb., 6,336,512 ; 

 the small numbers of the cartilaginous fishes have been already referred to. 



One reason adduced for sea fishes not requiring protection at any period 

 of their lives is that they deposit so many eggs, and that these will suffice 

 to meet all and every device man may employ to effect their capture. Here 

 the zoologist may well inquire whether breeding in fishes differs from what 

 obtains in the remainder of the animal kingdom, wherein the powers of 

 increase have been apportioned to the needs of the individual, for where 

 man has interfered, as in birds, ground game, seals, &c, protection has had 

 to be afforded in order to prevent annihilation of the species. It would 



