88 
able coa litions prevailed for stocking with fry, and in one 
other the conditions were adverse for stocking with year- 
lings. One of the streams, the Upper Gibson River, con- 
tained the blob, or miller’s thumb (Cottus bairdi punctu- 
latus), and in the other, the Yellowstone River, the native 
mountain trout (Salmo mykiss) was abundant. The in- 
fernally destructive propensities of the miller’s thumb are 
too well known to need remark here. The native trout of 
the Yellowstone has well been called voracious, and to 
him has been credited the destruction of at least one entire 
plant of fry. Prof. Everman, reporting on his reconnois- 
sance of these waters, made in the summer of 1891, says: 
‘‘At least the brook and Loch Leven trout, which were 
planted in 1889, spawned in 1890, as we found young of 
these species that could not be over a year old.’? Here is 
detinite proof that yearlings planted in a stream are capa- 
ble of reproducing and rearing their young, under condi- 
tions which would have, we may fairly say, been detri- 
mental if not destructive to a plant of fry. How this was 
accomplished will, [ think, show why it will not be neces- 
sary to annually restock a stream with yearlings because 
fry would not primarily live init. That the trout do not 
exercise any direct parental care (one of the most potent 
and necessary factors in the reproductions of animals in 
general) I freely concede, and yet more freely that the 
young fry are under natural environment at all times the 
prey of numberless enemies. It is not asking too much to 
suppose that the yearlings would and do destroy, either as 
food or from self-protection, and in some cases from wan- 
tonness, very much of the animal life which would other- 
wise find a ready and acceptable subsistence upon the eggs 
and fry of the trout in the following year. It may be 
too much to state, but at least it cannot be contra-proved, 
that the adult- trout destroys many of these enemies of 
their young from a sense of the necessity of the case. The 
yearling and the adult fish when planted in new waters in 
