42 TROUT CULTURE. 



Seasons vary, and times of spawning vary (though 

 within comparatively narrow limits), consequently no 

 hard and fast rule as to time of incubation can be laid 

 down. Late eggs may very likely hatch in a far 

 shorter time than early ones, as the water at the end of 

 February, and in March and April, will be warming up, 

 and consequently the development of the embryo will 

 be more rapid. 



No one, however, should be anxious to see the eggs 

 hatch out quickly ; the more slowly they hatch the 

 better, healthier, and stronger will the fish be. If the 

 eggs have "eyed" out strongly, and the form of the 

 fish be dark and lusty in the egg, let no one have any 

 anxiety about earliness of breaking the shell. 



Some day or other a little dark-looking thing will be 

 seen in one or other of the troughs, and an attempt be 

 made to remove it with the nippers, when the little 

 object will wriggle away and seek protection amongst 

 the eggs. These at this period appear much swollen, 

 and of a tint and with a bloom like a ripe peach. On 

 examining the little stranger in the glass tube, it will 

 appear as a mere threadlike body, with two very 

 prominent eyes, resting on a round yellow ball of oil. 

 On using a lens it will be seen that the blood-vessels 

 are spread out into and over this vesicle of oil or yolk, 

 whence the necessary food is obtained in this, which 

 is called the " Alevin " stage of a trout's existence. 



Nature thus caters for the young fish for from a 

 month to seven or eight weeks, according to tempera- 

 ture ; heat accelerating and cold retarding the con- 

 sumption of the oil in the vesicle and the development 

 of the body. Having all its needs supplied, it rests 

 pretty quietly for a day or two, and only wriggles at 



