LARGE AND ANXIOUS FAMILIES. 41 



CHAPTER H. 



FECUNDITY OF FISHES. 



FIRST. Mammalia, including whales, porpoises, and all fish- 

 es which bring forth alive and suckle their young, whether 

 herbivorous or carnivorous, seldom have more than one or 

 two young at a birth, which sailors term calves. 



Second. The families of which the salmon and trout are 

 the heads are called by naturalists the genus Salmo. These 

 fishes have the palpable mark of an adipose second dorsal 

 fin ; their meat is of a tint between mallow and pink, and 

 they are regarded by anglers and epicures as the highest 

 game and most luxurious fishes of the oviparous class, or 

 those fishes which replenish their species by laying eggs, 

 which are vivified by the milt of the male, and then, after a 

 time, the eggs hatch in the water. This process is common 

 to all egg-laying fishes ; but, while eggs of the salmo genus 

 require from three to four months to hatch, those of the clip- 

 ped genus hatch in as many days. Seth Green hatched shad 

 artificially on the Connecticut River within forty hours from 

 the time the ova and milt fell into the hatching-boxes in the 

 stream. being the main current of the river and not in 

 boxes so placed as that a stream should run through or over 

 them, but anchored so as to float in the current of the river, 

 submerging a sufficient portion of them for keeping the eggs 

 covered with water to a sufficient depth. A salmon is sup- 

 posed to lay a thousand eggs for every pound the mother 

 fish weighs, consequently they average from ten to thirty 

 thousand for each pair. 



Third. Included in this class are all the oviparous tribes 

 but those of the genus Salmo. The number of eggs in the 



