20 
BULIvETIN of thf bureau of fisheries 
There is usually no narrowing just outside the nucleus to form a “core,” but this may 
be present in a faint form, or occasionally be more pronounced. 
Subsequent years’ growths are usually about equal, the well-formed winter bands 
about equally spaced and very strongly marked. Occasional exceptions occur, in which 
the second summer’s growth has been unusually wide and the third summer’s growth 
much less so, with the result that the second and third winter bands are more closely 
apposed than usual. Such cases must be distinguished from others in which a double 
second winter band occurs, or an “intercalated check,” during the latter part of the 
summer. In instances of the latter class there are usually irregularities in the develop- 
ment of the redundant band in different scales, also fusions of the two bands here and 
there. There is also a lack of any very sudden break or change in character of the rings 
outside a redundant band, and no unconformity in the rings, characters which very 
generally accompany the new year’s growth. 
At the ist of August, when our series of scales were taken, the rings of the outer 
summer zone had in all cases begun to narrow into the winter band. The great thick- 
ness of the winter bands in this species may be in part thus explained. They may 
represent more than half the year’s growth, beginning perhaps in July and continuing 
until the new year’s growth commences at some period in the spring. Material collected 
at Seattle the last of April, 1911, did not include this species, but in the king salmon 
smaller individuals had then produced from two to six broad rings of the new growth, 
and larger ones (from 18 inches up) contained usually no new growth. If this holds 
also in the dog salmon, the winter bands represent growth at ever-decreasing rate from 
July to May of the following year, the few wide summer rings representing sudden 
vigorous growth for but two or three months. This is of course insufficiently established. 
Taking the great majority of specimens (in at least 90 per cent), the scales are 
perfectly typical and schematic, a glance with the aid of a simple lens being adequate 
to determine the age. This regularity and simplicity is also evident in the humpback 
salmon, and is in both species to be attributed to the fact that the young all have the 
same history, proceeding at once to sea, whereas in the other species, as has been shown, 
a dual habit is found. 
Prof. McMurrich’s contention that the dog salmon is a 4-year fish, with a nuclear 
area representing life in fresh water, has already been sufficiently answered. Plate viil 
of his article has unfortunately the nuclear area so blurred in reproduction that its 
character can not be positively determined. If, however, this area was close-ringed 
“as in the sockeye and spring salmon, a central nucleus surrounded by a zone of fresh- 
water lines,” the scale could hardly belong to the dog salmon. Such a description 
could not apply to plate ix, which represents obviously a 3-year-old scale, with the 
medial portion of the first winter band very narrowly divided but the two portions 
wholly fused at the sides. The significance of the so-called “spawning mark” we do 
not here discuss. 
