CARE OF ALEVINS. I4I 



the ground again quite out of breath, with their little 

 hearts beating very fast, as is not surprising, consider- 

 ing their age, and that they carry about a burden 

 twice the bulk of their bodies proper. They require 

 no watching nor care of any kind for the first few days. 

 They do not try to get away, they do not require to be 

 fed, and if the hatching apparatus is well arranged, and 

 throws a good supply of water over them, very few 

 will die. Indeed, the yolk-sac period is one of the 

 healthiest of the trout's early life. 



They seem at first to be possessed of no particular 

 instincts, but lie still near the spot where they were 

 born, and do nothing. This, however, lasts only a few 

 days.* They are soon seized, sometimes very sud- 



* The following notes are taken from the writer's diary, Janu- 

 ary, 1869. 



The embryos observed, were hatched from salmon eggs 

 brought from the Mirimichi River. They were kept in a warm 

 room, at a temperature that would probably make one day an 

 equivalent of two or three days in the hatching trough at 45°. 



J^/rs^ day. Eggs hatched to-day. Young fish quite vigorous. 

 Yolk sac plump and full. Body proper, thin, and delicate, and 

 with cloudy outline. 



Second day. Change very slight. Outline a little more distinct. 

 Body darker. Sac not quite so plump. 



Third day. Changes of yesterday slightly intensified. Beating 

 of the heart very perceptible. Main artery distinctly seen. 



Fourth day. Form of yolk sac decidedly changed. Body firm- 

 er and darker. Eyes very clear. Motion of fins quite per- 

 ceptible. 



Fifth day. Fish much livelier. A new movement of the tail 

 observed. 



Sixth day. Yolk sac very considerably changed, and contract- 

 ing towards a point at the lower end. Other blood passages 

 clearly perceptible. 



