186 EEPORT OF COMMISSIONER OF FISH AND FISHERIES. 



Answer. Tlie rate of growth per annum is not known. The grilse 

 in the MeCloud Kiver, which w^ere supposed to be eighteen months okl, 

 measured from 18 to 24 inches in length. The theory is that salmon are 

 full-grown at tbe age of about three years. It is also known that the 

 young salmon in the McCloud, in May, are 2 or 3 iucheslong, from which 

 the following conjectural table may be formed : 



Lenglh. 



Young fry, a few months old 2 or 3 inches. 



Grilse, eighteen months old 18 to 24 inches. 



Salmon, about three years old, (average) 30 inches. 



Question 10. Do the sexes differ in respect to shape, size, rate of 

 growth, etc. ? 



Answer. During the fresh runs of the winter and spring, the sexes 

 difier very slightly, if any, in sha|)e or general appearance. The male 

 may possibly be a little more curved in the jaws, and a little less plump 

 along the sides of the abdomen, but these differences are but slightlj' 

 defined. The difference is also very slight through the summer, but in 

 the fall the distinctions of the sexes are very marked. The now fully 

 developed ova of the female gives her sex a peculiarly rounded and 

 plump ap])earance, and the shape and expression of her head does not 

 change much. On the other hand the male grows very deep and thin. 

 His head flattens, his upper jaw curves like a hook over the lower, his 

 eyes assume a peculiarly sunken and malicious expression. Large, 

 powerful white teeth, like dog's teeth, appear on both jaws, and the whole 

 creature acquires an ugly and ferocious appearance. As 'to the com- 

 parative rate of growth of the two sexes, although I have not noticed 

 that the males are larger than the females in winter and spring, I have 

 always observed that they are considerably larger in the spawning sea- 

 son. Allowing the average age of both sexes to be the same, it would 

 consequently appear that the rate of growth of the males is greater than 

 that of the females. 



E. — MiG-RATIONS AND MOVEMENTS. 



Question 11. By what route do these flsh come in to the shore 5 and 

 what the subsequent movements "I 



Answer. All the fishermen agree that most of the Sacramento salmon 

 come down the coast from the Xorth. On arriving at the mouth of the 

 river they spend some time in the bay of San Francisco. Two weeks 

 after their arrival in the bay, they make their appearance at the head 

 of tide-water. At this point they seem to "wait some time, the fishermen 

 being of the opinion that they play about here for a period, and actu- 

 ally go up a little ways into fresh water and return to tide-water again. 

 It is more than four months after their appearance in the bay of San 

 Francisco before they enter the colder tributaries of the river, as, for 

 instance, the McCloud and Little Sacramento, one hundred and seventy 

 miles north of the head of tide-water. They do not reach the sources 



