164 
ZOOLOGY. 
laid in shallow holes made in the gravel of streams. The 
extreme young is banded and called parr; when about a 
year old, and of a bright silvery color, before descending 
the rivers to the sea, it is called a smolt; after its return 
from the sea into fresh water it goes by the name of grilse; 
and finally, after returning a second time from the sea, it 
assumes its name of salmon. The trout {Salmo fontinalis) 
also breeds in the autumn and early winter; it is not mi- 
gratory, living permanently in streams and ponds. 
An allied family embraces the smelt (Fig. 207). The 
capelin {Mallotus villosus) is valuable as bait in the cod 
fishery. It spawns in the summer. The males are distin- 
Fia. 207.-/riie Smelt, Osmerus mordaar, one half natural size. 
guished by a prominent lateral ridge along the sides of the 
body, and are more numerous than the females. 
The carps {Cyprimis), shiners, and minnows abound 
everywhere in the Northern States in ponds and weedy 
r)treams. The breeding habits of the dace {RhmicMhys 
atronasus) are interesting. The females spawn over " nests" 
or shallow depressions two feet in diameter in running 
brooks about a foot deep; the male 2:)asses over the eggs fer- 
tilizing them; then the pair bring small pebbles which are 
dropped over the eggs, until layer after layer alternately of 
eggs and pebbles are deposited, when a heap is formed, the 
young hatching out and remaining among the pebbles until 
old enough to venture out into the stream. The dcice is 
closely allied to the chub {Semotihts rhotheus, Fig. 209). 
