18893 Man s Part in Distribution 



quartzite, red and gray. But whatever the cause, 

 protection from an osprey or kingfisher looking down 

 into the shallow, open ripples must be fairly sure. 



Another case of seemingly anomalous dispersion 

 relates to the presence of the Lake Tahoe trout — 

 Salmo henshawi — in the plateau tributaries of the 

 Feather River, a large stream emptying into the 

 Sacramento. After careful consideration of Plumas 

 County dykes, I was prepared for a topographic 

 explanation of the problem. Fortunately, however, Helping 

 I met Mr. Pratt, a local resident, who had himself ^^^^'^out 

 carried henshawi from the Truckee, the outlet of 

 Tahoe, and put them in the headwaters of the 

 Feather at Prattville. Recent operations of the Fish 

 Commission have scattered alien species throughout 

 California, so that the Eastern Brook Trout and the 

 European Brown Trout, celebrated by Izaak Walton, 

 now also abound in the Feather, in addition to an 

 indigenous Rainbow. On the other hand, in 1913, I 

 found the Shasta Rainbow on sale at Arlon in the 

 hills of Belgian Luxembourg. 



c 343 n 



