The Californian Salmon. 49 



Joaquin river is 79*7 deg. During the same 

 period the mean temperature of the Sacra- 

 mento, calculated over ten years, is 73*4 deg. 



"A point equally important is that this 

 species does not suffer although the water 

 may be somewhat impure ; it ascends the 

 Sacramento and San Joaquin at the precise 

 time when the waters are most affected by the 

 washing of minerals, and seems to feel no 

 inconvenience. 



" The time of spawning of this salmon is 

 prolonged excessively, contrary to that of the 

 Salmo solar, and seems to last nearly six 

 months of the year. It is known that the 

 period varies according to the locality, being 

 earlier in proportion to the distance from the 

 sea, and near the source of the rivers. Thus 

 in the upper waters of the Sacramento the 

 spawning takes place in the end of June or 

 the beginning of July; 30 miles lower down 

 the stream it is observed to take place in July 

 and August, and the farther down the river 

 the later is the time of spawning. At the 

 junction of the McCloud river with the Sacra- 

 mento, or about 180 miles from the sea, it 

 does not take place till the end of August, or 



