60 SCIENCE SKETCHES. 
River is more likely, on that account, to return to 
the Clackamas than to go up the Cowlitz or the 
Des Chites. “At the hatchery on Rogue River, 
the fish are stripped, marked, and set free, and 
every year since the hatchery has been in opera- 
tion some of the marked fish have been re-caught. 
The young fry are also marked, but none of them 
have been re-caught.” The shad is another spe- 
cies of fish supposed to possess this remarkable 
homing instinct. Shad have been planted in the 
Sacramento River, and considerable numbers de- 
scended from this plant have been already taken 
in the Columbia River and in Monterey Bay, but 
not a single one, so far as known to me, in the origi- 
nal stream, the Sacramento. 
In regard to the diminution of the number of 
salmon on the coast we may make these observa- 
tions. In Puget Sound, Frazer River, and the 
small streams, there appears to be little or no evi- 
dence of diminution. In the Columbia River the 
evidence appears somewhat conflicting. The catch 
in 1880 was considerably greater than ever before 
(nearly 540,000 cases of 48 pounds each having 
been packed), although the fishing for three or 
four years has been very extensive. On the other 
hand, the high water of that year undoubtedly 
caused many fish to become spring salmon which 
would otherwise have run in the fall. Moreover, 
it is urged that a few years ago, when the number 
caught was about half as great as in 1880, the 
amount of netting used was perhaps one eighth as 
much. With a comparatively small outfit the can- 
ners caught half the fish; now, with nets much 
