TROUT BREEDING. 63 



" On the thirteenth day the circle has passed three- 

 fourths round the egg, a side view being represented by 

 figure 10. 



" On the fourteenth day the circle has passed entirely 

 over the egg and the young trout is formed, as shown in 

 figure 11. 



" On the twenty-fifth day, the eyes, heart, arteries, red 

 blood, circulation of blood and motion will be observed. 

 The egg and young fish at this stage is pictured in figure 

 12. (^ About the fiftieth day the young trout will begin to 

 come out of the shell, and continue to do so for some days 

 or a week." ^ 



I have some notes and memoranda of my own on incuba- 

 tion, but the foregoing is so brief, and yet so comprehen- 

 sive, that I have preferred giving it. In referring to the 

 little plate of figures, Mr. Ainsworth, in a recent letter, 

 says : " It would have been a great advantage to me in the 

 beginning of my experiments, and I hope it will be of 

 much benefit to those who attempt the artificial propagation 

 of trout, as they will see at a glance what has taken me 

 nine years to learn." 



Mr. Ainsworth has also arranged the following table, 

 giving the temperature of the water from 37° to 54°, show- 

 ing the progress of development, the time of incubation, 

 and at what time the young fish will commence feeding. 

 This table is made from memoranda he has kept of all the 

 spawn he has taken for four years; he says : "I have esti- 

 mated a little in the higher and lower figures as to the time 

 of hatching, as my water did not hold at these degrees long 

 enough to hatch the ova.'' 



