Scientific American Supplement No. 275

V >> Various >> Scientific American Supplement No. 275

Pages:
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11

Prof. S. spoke of the remedies for root lice, among which were hot water
and bisulphide of carbon. Hot water will get cold before it can reach the
smaller roots, however efficient it may be showered on leaves. Bisulphide
of carbon is very volatile, inflammable, and sometimes explosive, and must
be handled with great care. It permeates the soil, and if in sufficient
quantity may be effective in destroying the phylloxera; but its cost and
dangerous character prevent it from being generally recommended.

Paris green is most generally useful for destroying insects. As sold to
purchasers, it is of various grades of purity. The highest in price is
commonly the purest, and really the cheapest. A difficulty with this
variable quality is that it cannot be properly diluted with water, and
those who buy and use a poor article and try its efficacy, will burn or
kill their plants when they happen to use a stronger, purer, and more
efficient one. Or, if the reverse is done, they may pronounce it a humbug
from the resulting failure. One teaspoonful, if pure, is enough for a large
pail of water; or if mixed with flour, there should be forty or fifty times
as much. Water is best, as the operator will not inhale the dust. London
purple is another form of the arsenic, and has very variable qualities
of the poison, being merely refuse matter from manufactories. It is more
soluble than Paris green, and hence more likely to scorch plants. On the
whole, Paris green is much the best and most reliable for common use.

At the close of Prof. Saunders' remarks some objections were made by
members present to the use of Paris green on fruit soon after blossoming,
and Prof. S. sustained the objection, in that the knowledge that the fruit
had been showered with it would deter purchasers from receiving it, even if
no poison could remain on it from spring to autumn. A man had brought to
him potatoes to analyze for arsenic, on which Paris green had been used,
and although it was shown to him that the poison did not reach the roots
beneath the soil, and if it did it was insoluble and could not enter them,
he was not satisfied until a careful analysis was made and no arsenic at
all found in them. A member said that in mixing with plaster there should
be 100 or 150 pounds of plaster to one of the Paris green, and that a
smaller quantity, by weight, of flour would answer, as that is a more bulky
article for the same weight.

* * * * *

OBSERVATIONS ON THE SALMON OF THE PACIFIC.

By DAVID S. JORDAN and CHAS. H. GILBERT.

During the most of the present year, the writers have been engaged in the
study of the fishes of the Pacific coast of the United States, in the
interest of the U.S. Fish Commission and the U.S. Census Bureau. The
following pages contain the principal facts ascertained concerning the
salmon of the Pacific coast. It is condensed from our report to the U.S.
Census Bureau, by permission of Professor Goode, assistant in charge of
fishery investigations.

There are five species of salmon (Oncorhynchus) in the waters of the North
Pacific. We have at present no evidence of the existence of any more on
either the American or the Asiatic side.

These species may be called the quinnat or king salmon, the blue-back
salmon or red-fish, the silver salmon, the dog salmon, and the hump-back
salmon, or _Oncorhynchus chouicha, nerka, kisutch, keta_, and _gorbuscha_.
All these species are now known to occur in the waters of Kamtschatka as
well as in those of Alaska and Oregon.

As vernacular names of definite application, the following are on record:

a. Quinnat--Chouicha, king salmon, e'quinna, saw-kwey, Chinnook salmon,
Columbia River salmon, Sacramento salmon, tyee salmon, Monterey salmon,
deep-water salmon, spring salmon, ek-ul-ba ("ekewan") (fall run).

b. Blue-bock--krasnaya ryba, Alaska red-fish, Idaho red fish, sukkegh,
Frazer's River salmon, rascal, oo-chooy-ha.

c. Silver salmon--kisutch, winter salmon, hoopid, skowitz, coho, bielaya
ryba, o-o-wun.

d. Dog salmon--kayko, lekai, ktlawhy, qualoch, fall salmon, o-le-a-rah. The
males of _all_ the species in the fall are usually known as dog salmon, or
fall salmon.

e. Hump-back--gorbuscha, haddo, hone, holia, lost salmon, Puget Sound
salmon, dog salmon (of Alaska).

Of these species, the blue-back predominates in Frazer's River, the silver
salmon in Puget Sound, the quinnat in the Columbia and the Sacramento, and
the silver salmon in most of the small streams along the coast. All the
species have been seen by us in the Columbia and in Frazer's River; all
but the blue-back in the Sacramento, and all but the blue-back in waters
tributary to Puget Sound. Only the quinnat has been noticed south of San
Francisco, and its range has been traced as far as Ventura River, which is
the southernmost stream in California which is not muddy and alkaline at
its mouth.

Of these species, the quinnat and blue-back salmon habitually "run" in the
spring, the others in the fall. The usual order of running in the rivers is
as follows: _nerka, chouicha, kisutch, gorbuscha, keta_.

The economic value of the spring running salmon is far greater than that of
the other species, because they can be captured in numbers when at their
best, while the others are usually taken only after deterioration.

The habits of the salmon in the ocean are not easily studied. Quinnat and
silver salmon of every size are taken with the seine at almost any season
in Puget Sound. The quinnat takes the hook freely in Monterey bay, both
near the shore and at a distance of six or eight miles out. We have reason
to believe that these two species do not necessarily seek great depths, but
probably remain not very far from the mouth of the rivers in which they
were spawned.

The blue-back and the dog salmon probably seek deeper water, as the former
is seldom or never taken with the seine in the ocean, and the latter is
known to enter the Straits of Fuca at the spawning season.

The great majority of the quinnat salmon and nearly all blue-back salmon
enter the rivers in the spring. The run of both begins generally the last
of March; it lasts, with various modifications and interruptions, until
the actual spawning season in November; the time of running and the
proportionate amount of each of the subordinate runs, varying with each
different river. In general, the runs are slack in the summer and increase
with the first high water of autumn. By the last of August only straggling
blue-backs can be found in the lower course of any stream, but both in the
Columbia and the Sacramento the quinnat runs in considerable numbers till
October at least. In the Sacramento the run is greatest in the fall, and
more run in the summer than in spring. In the Sacramento and the smaller
rivers southward, there is a winter run, beginning in December.

The spring salmon ascend only those rivers which are fed by the melting
snows from the mountains, and which have sufficient volume to send their
waters well out to sea. Such rivers are the Sacramento, Rogue, Klamath,
Columbia, and Frazer's rivers.

Those salmon which run in the spring are chiefly adults (supposed to be at
least three years old). Their milt and spawn are no more developed than at
the same time in others of the same species which will not enter the rivers
until fall. It would appear that the contact with cold fresh water, when in
the ocean, in some way caused them to turn toward it and to "run," before
there is any special influence to that end exerted by the development of
the organs of generation.

High water on any of these rivers in the spring is always followed by an
increased run of salmon. The canners think, and this is probably true, that
salmon which would not have run till later are brought up by the contact
with the cold water. The cause of this effect of cold fresh water is not
understood. We may call it an instinct of the salmon, which is another way
of expressing our ignorance. In general, it seems to be true that in those
rivers and during those years when the spring run is greatest, the fall run
is least to be depended on.

As the season advances, smaller and younger salmon of these two species
(quinnat and blue-back) enter the rivers to spawn, and in the fall these
young specimens are very numerous. We have thus far failed to notice any
gradations in size or appearance of these young fish by which their ages
could be ascertained. It is, however, probable that some of both sexes
reproduce at the age of one year. In Frazer's River, in the fall, quinnat
male grilse of every size, from eight inches upward, were running, the milt
fully developed, but usually not showing the hooked jaws and dark colors
of the older males. Females less than eighteen inches in length were rare.
All, large and small, then in the river, of either sex, had the ovaries or
milt well developed.

Little blue-backs of every size down to six inches are also found in
the Upper Columbia in the fall, with their organs of generation fully
developed. Nineteen twentieths of these young fish are males, and some of
them have the hooked jaws and red color of the old males.

The average weight of the quinnat in the Columbia in the spring is
twenty-two pounds; in the Sacramento about sixteen. Individuals weighing
from forty to sixty pounds are frequently found in both rivers, and some as
high as eighty pounds are reported. It is questioned whether these large
fishes are:

(_a_.) Those which, of the same age, have grown more rapidly;

(_b_.) Those which are older but have, for some reason, failed to spawn;
or,

(_c_.) Those which have survived one or more spawning seasons.

All of these origins may be possible in individual cases; we are, however,
of the opinion that the majority of these large fish are those which have
hitherto run in the fall and so may have survived the spawning season
previous.

Those fish which enter the rivers in the spring continue their ascent until
death or the spawning season overtakes them. Probably none of them ever
return to the ocean, and a large proportion fail to spawn. They are known
to ascend the Sacramento as far as the base of Mount Shasta, or to its
extreme head-waters, about four hundred miles. In the Columbia they are
known to ascend as far as the Bitter Root Mountains, and as far as the
Spokan Falls, and their extreme limit is not known. This is a distance of
six to eight hundred miles.

At these great distances, when the fish have reached the spawning grounds,
besides the usual changes of the breeding season, their bodies are covered
with bruises on which patches of white fungus develop. The fins become
mutilated, their eyes are often injured or destroyed; parasitic worms
gather in their gills, they become extremely emaciated, their flesh
becomes white from the loss of the oil, and as soon as the spawning act
is accomplished, and sometimes before, all of them die. The ascent of the
Cascades and the Dalles probably causes the injury or death of a great many
salmon.

When the salmon enter the river they refuse bait, and their stomachs are
always found empty and contracted. In the rivers they do not feed, and when
they reach the spawning grounds their stomachs, pyloric coeca and all, are
said to be no larger than one's finger. They will sometimes take the
fly, or a hook baited with salmon roe, in the clear waters of the upper
tributaries, but there is no other evidence known to us that they feed when
there. Only the quinnat and blue-back (then called red-fish) have been
found in the fall at any great distance from the sea.

The spawning season is probably about the same for all the species. It
varies for all in different rivers and in different parts of the same
river, and doubtless extends from July to December.

The manner of spawning is probably similar for all the species, but we have
no data for any except the quinnat. In this species the fish pair off, the
male, with tail and snout, excavates a broad shallow "nest" in the gravelly
bed of the stream, in rapid water, at a depth of one to four feet; the
female deposits her eggs in it, and after the exclusion of the milt, they
cover them with stones and gravel. They then float down the stream tail
foremost. A great majority of them die. In the head-waters of the large
streams all die, unquestionably. In the small streams, and near the sea, an
unknown percentage probably survive. The young hatch in about sixty days,
and most of them return to the ocean during the high water of the spring.

The salmon of all kinds in the spring are silvery, spotted or not according
to the species, and with the mouth about equally symmetrical in both sexes.

As the spawning season approaches the female loses her silvery color,
becomes more slimy, the scales on the back partly sink into the skin, and
the flesh changes from salmon red and becomes variously paler, from the
loss of the oil, the degree of paleness varying much with individuals and
with inhabitants of different rivers.

In the lower Sacramento the flesh of the quinnat in either spring or fall
is rarely pale. In the Columbia, a few with pale flesh are sometimes taken
in spring, and a good many in the fall. In Frazer's River the fall run of
the quinnat is nearly worthless for canning purposes, because so many are
white meated. In the spring very few are white meated, but the number
increases towards fall, when there is every variation, some having red
streaks running through them, others being red toward the head and pale
toward the tail. The red and pale ones cannot be distinguished externally,
and the color is dependent neither on age nor sex. There is said to be no
difference in the taste, but there is no market for canned salmon not of
the conventional orange color.

As the season advances, the differences between the males and the females
become more and more marked, and keep pace with the development of the
milt, as is shown by dissection.

The males have: (_a_.) The premaxillaries and the tip of the lower jaw
more and more prolonged; both of them becoming finally strongly and often
extravagantly hooked, so that either they shut by the side of each other
like shears, or else the mouth cannot be closed. (_b_.) The front teeth
become very long and canine-like, their growth proceeding very rapidly,
until they are often half an inch long. (_c_.) The teeth on the vomer and
tongue often disappear. (_d_.) The body grows more compressed and deeper
at the shoulders, so that a very distinct hump is formed; this is more
developed in _0. gorbuscha_, but is found in all. (_e_.) The scales
disappear, especially on the back, by the growth of spongy skin. (_f_.) The
color changes from silvery to various shades of black and red or blotchy,
according to the species. The blue-back turns rosy red, the dog salmon a
dull, blotchy red, and the quiunat generally blackish.

These distorted males are commonly considered worthless, rejected by the
canners and salmon-salters, but preserved by the Indians. These changes are
due solely to influences connected with the growth of the testes. They are
not in any way due to the action of fresh water. They take place at about
the same time in the adult males of all species, whether in the ocean or
in the rivers. At the time of the spring runs all are symmetrical. In the
fall, all males of whatever species are more or less distorted. Among the
dog salmon, which run only in the fall, the males are hooked-jawed and
red-blotched when they first enter the Straits of Fuca from the outside.
The hump-back, taken in salt water about Seattle, shows the same
peculiarities. The male is slab-sided, hook-billed, and distorted, and is
rejected by the canners. No hook-jawed _females_ of any species have been
seen.

It is not positively known that any hook-jawed male survives the
reproductive act. If any do, their jaws must resume the normal form.

On first entering a stream the salmon swim about as if playing: they always
head toward the current, and this "playing" may be simply due to facing the
flood tide. Afterwards they enter the deepest parts of the stream and swim
straight up, with few interruptions. Their rate of travel on the Sacramento
is estimated by Stone at about two miles per day; on the Columbia at about
three miles per day.

As already stated, the economic value of any species depends in great part
on its being a "spring salmon." It is not generally possible to capture
salmon of any species in large numbers until they have entered the rivers,
and the spring salmon enter the rivers long before the growth of the organs
of reproduction has reduced the richness of the flesh. The fall salmon
cannot be taken in quantity until their flesh has deteriorated: hence the
"dog salmon" is practically almost worthless, except to the Indians, and
the hump-back salmon is little better. The silver salmon, with the same
breeding habits as the dog salmon, is more valuable, as it is found in
Puget Sound for a considerable time before the fall rains cause the fall
runs, and it may be taken in large numbers with seines before the season
for entering the rivers. The quinnat salmon, from its great size and
abundance, is more valuable than all other fishes on our Pacific coast
together. The blue back, similar in flesh but much smaller and less
abundant, is worth much more than the combined value of the three remaining
species.

The fall salmon of all species, but especially the dog salmon, ascend
streams but a short distance before spawning. They seem to be in great
anxiety to find fresh water, and many of them work their way up little
brooks only a few inches deep, where they soon perish miserably,
floundering about on the stones. Every stream, of whatever kind, has more
or less of these fall salmon.

It is the prevailing impression that the salmon have some special instinct
which leads them to return to spawn in the same spawning grounds where they
were originally hatched. We fail to find any evidence of this in the case
of the Pacific coast salmon, and we do not believe it to be true. It seems
more probable that the young salmon, hatched in any river, mostly remain in
the ocean within a radius of twenty, thirty, or forty miles of its mouth.
These, in their movements about in the ocean, may come into contact with
the cold waters of their parent rivers, or perhaps of any other river, at
a considerable distance from the shore. In the case of the quinnat and the
blue-back, their "instinct" leads them to ascend these fresh waters, and
in a majority of cases these waters will be those in which the fishes in
question were originally spawned. Later in the season the growth of the
reproductive organs leads them to approach the shore and to search for
fresh waters, and still the chances are that they may find the original
stream. But undoubtedly many fall salmon ascend, or try to ascend, streams
in which no salmon was ever hatched.

It is said of the Russian River and other California rivers, that their
mouths in the time of low water in summer generally become entirely closed
by sand bars, and that the salmon, in their eagerness to ascend them,
frequently fling themselves entirely out of water on the beach. But this
does not prove that the salmon are guided by a marvelous geographical
instinct which leads them to their parent river. The waters of Russian
River soak through these sand bars, and the salmon "instinct," we think,
leads them merely to search for fresh waters.

This matter is much in need of further investigation; at present, however,
we find no reason to believe that the salmon enter the Rogue River simply
because they were spawned there, or that a salmon hatched in the Clackamas
River is any the more likely on that account to return to the Clackamas
than to go up the Cowlitz or the Deschutes.

"At the hatchery on Rogue River, the fish are stripped, marked and set
free, and every year since the hatchery has been in operation some of the
marked fish have been re-caught. The young fry are also marked, but none of
them have been recaught."

This year the run of silver salmon in Frazer's River was very light, while
on Puget Sound the run was said by the Indians to be greater than ever
known before. Both these cases may be due to the same cause, the dry
summer, low water, and consequent failure of the salmon to find the rivers.
The run in the Sound is much more irregular than in the large rivers. One
year they will abound in one bay and its tributary stream and hardly be
seen in another, while the next year the condition will be reversed. At
Cape Flattery the run of silver salmon for the present year was very small,
which fact was generally attributed by the Indians to the birth of twins at
Neah Bay.

In regard to the diminution of the number of salmon on the coast. In
Puget's Sound, Frazer's River, and the smaller streams, there appears to be
little or no evidence of this. In the Columbia River the evidence appears
somewhat conflicting; the catch during the present year (1880) has been
considerably greater than ever before (nearly 540,000 cases of 48 lb. each
having been packed), although the fishing for three or four years has been
very extensive. On the other hand, the high water of the present spring has
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 now, the amount of netting used
was perhaps one-eighth as much. With a comparatively small outfit the
canners caught half the fish, now with nets much larger and more numerous,
they catch them all, scarcely any escaping during the fishing season (April
1 to August 1). Whether an actual reduction in the number of fish running
can be proven or not, there can be no question that the present rate of
destruction of the salmon will deplete the river before many years. A
considerable number of quinnat salmon run in August and September, and some
stragglers even later; these now are all which keep up the supply of
fish in the river. The non-molestation of this fall run, therefore, does
something to atone for the almost total destruction of the spring run.

This, however, is insufficient. A well-ordered salmon hatchery is the only
means by which the destruction of the salmon in the river can be prevented.
This hatchery should be under the control of Oregon and Washington, and
should be supported by a tax levied on the canned fish. It should be placed
on a stream where the quinnat salmon actually come to spawn.

It has been questioned whether the present hatchery on the Clackamas River
actually receives the quinnat salmon in any numbers. It is asserted, in
fact, that the eggs of the silver salmon and dog salmon, with scattering
quinnat, are hatched there. We have no exact information as to the truth of
these reports, but the matter should be taken into serious consideration.

On the Sacramento there is no doubt of the reduction of the number of
salmon; this is doubtless mainly attributable to over-fishing, but in part
it may be due to the destruction of spawning beds by mining operations and
other causes.

As to the superiority of the Columbia River salmon, there is no doubt that
the quinnat salmon average larger and fatter in the Columbia than in the
Sacramento and in Puget Sound. The difference in the canned fish is,
however, probably hardly appreciable. The canned salmon from the Columbia,
however, bring a better price in the market than those from elsewhere. The
canners there generally have had a high regard for the reputation of
the river, and have avoided canning fall fish or species other than the
quinnat. In the Frazer's River the blue-back is largely canned, and its
flesh being a little more watery and perhaps paler, is graded below the
quinnat. On Puget Sound various species are canned; in fact, everything
with red flesh. The best canners on the Sacramento apparently take equal
care with their product with those of the Columbia, but they depend largely
on the somewhat inferior fall run. There are, however, sometimes salmon
canned in San Francisco, which have been in the city markets, and for some
reason remaining unsold, have been sent to the canners; such salmon are
unfit for food, and canning them should be prohibited.

The fact that the hump-back salmon runs only on alternate years in Puget
Sound (1875, 1877, 1879, etc.) is well attested and at present unexplained.
Stray individuals only are taken in other years. This species has a
distinct "run," in the United States, only in Puget Sound, although
individuals (called "lost salmon") are occasionally taken in the Columbia
and in the Sacramento.--_American Naturalist._

* * * * *

THE RELATION BETWEEN ELECTRICITY AND LIGHT.

[Footnote: A lecture by Dr. O. J. Lodge, delivered at the London
Institution on December 16, 1880.]

Ever since the subject on which I have the honor to speak to you to-night
was arranged, I have been astonished at my own audacity in proposing to
deal in the course of sixty minutes with a subject so gigantic and so
profound that a course of sixty lectures would be quite inadequate for its
thorough and exhaustive treatment.

Pages:
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11