Strange Facts of Fish Life
The silvery body of the Sea Trout shown by a front light. Careful observation is
necessary to distinguish the Sea Trout from the sea-going Brown Trout.
similar scales, but differ in the arrangement of the teeth and certain appendages in
the digestive track.
5.-THE SALMON FAMILY
By DR. FRANCIS WARD, F.Z.S.
With photographs by the Author
E have already considered the
salmon and the brown trout, and
now propose to deal with the
other members of the family which we shall
call generally the salmonoids.
All salmonoids have a common origin.
As we shall see by the examples here
described, their primitive state is gradually
modified so that variations of appearance
and habit are brought about.
I have just looked into my copy of
" British Fresh-water Fishes " by the Rev.
W. Houghton, M.A., F.L.S., etc. ; it is
filled with beautiful illustrations.
This book has been out of print for
many years, but I found what I wanted
illustrations and descriptions of the
trout, in his various garbs, as described
by former writers. Here is the list as
given by Houghton : salmon trout, sewin,
bull trout, Gal way sea trout, common
trout, black-finned trout, Loch Stennis
THE PAGEANT OF NATURE
trout, Loch Leven trout, gillaroo trout,
Great Lake trout.
There is a Swedish saying : " A favourite
child has many names " the trout is a
favourite child. All the above names are
the names of this favourite child the
common brown trout in disguise.
Trout, with the rest of the salmon
Both can be acquired by food only. Of
course, there is a scheme behind this.
Either the trout must copy the pattern
of his surroundings mimicry or he must
To prove that this variation can occur
as a result of food and food only, I give
the following instance. On Mr. Rich-
Rainbow Trout under observation in the pond. Its prominent dark markings do not
render it so conspicuous as might be imagined, except when seen against a perfectly
uniformly shaded background.
family, can always be recognized as mem-
bers of that family by the presence of
the adipose fin the small fatty fin behind
the large fin on the back.
Yet, looking at the illustrations before
me, it is hard to realize that the common
brown trout can alter to such an extent,
and then revert to his original appearance,
when he returns to his usual habits and
Environment is undoubtedly an import-
ant factor in the alteration of the appear-
ance of fish. Yet the extent to which
food is responsible for variation in the
several disguises assumed by trout for
defensive purposes in their constant under-
water warfare, is not adequately recognized.
Bold markings and silvery iridescence are
the extremes of alteration in appearance.
mond's fish farm at Shottermill are two
ponds, less than two hundred yards apart.
These two ponds draw their water from
the same supply, but the food in each
happens to be of a totally different character.
This accident as accidents often do gives
useful information, in this instance on
fish coloration. The upper pond abounds
in water snails and other mollusca. The
food in the lower pond consists almost
entirely of crustaceans, water-fleas, daphnia,
Both these ponds were stocked at the
same time from the same hatch of fish.
Very soon, however, the fish in the upper
pond became dark in colour, with intense
red spots, and yellow below ; those in
the lower pond acquired a silvery appear-
ance, shot with a pale pink hue. The
STRANGE FACTS OF FISH LIFE
silvery appearance was due to a develop- lining of the stomach is also immensely
ment of an excessive amount of light thickened. What is the connexion ? Food !
reflecting spicules, on the scales of the In Loughs Melvin and Mask the main food
fish, known as iridocytes ; these iridocytes is bivalves and other molluscs ; this, as
consist of guanin, derived from a rich already explained, is the cause of the
crustacean diet. The peculiar pink shade brilliant coloration of this fish. The
that these fish had acquired was due to thickened stomach-wall is developed to
the masking of the colour cells in the triturate their tough diet,
skin by the excessive number of iridocytes. What about the salmon ? He is a near
When the brown trout goes to sea he relative of the trout, but years ago he took
has the opportunity of feeding on abund- a line of his own. Every now and then one
ance of guanin-forming
food, and so acquires a
silvery appearance. Inci-
dentally, this silvery ap-
pearance is his salvation,
for it converts him into
a mirror when seen from
under-water ; for he re-
flects his surroundings,
and so by reflection is
concealed from his
All the trout in Hough-
ton's list are merely brown
At one time there were
no trout in the Antipodes.
Ova were sent over from
England to Tasmania and
New Zealand. Very soon
the trout acquired sea-
going habits, and after
spending some time in the
sea returned to fresh water
to spawn as silvery fish, often weighing sees in the newspapers a paragraph headed
The silvery appearance of the Brown Trout converts him into
a mirror when seen from under-water, and so by reflection
conceals him from his enemies.
twenty pounds and more.
Salmon caught in the Thames," or, it
The young of these fish, if prevented may be, in some other waters equally
from going back to sea, regain the habits uncongenial to the King of Fish. On
and appearances of the ordinary common inquiry, the fish reported on turns out to
In British waters, bull trout are fish
acting in the same way.
be a sea trout.
It does not require an expert to distin-
guish between these two fish ; there is an
The Great Lake trout (Salmo ferox) is infallible sign by which a small salmon or a
a cannibal pure and simple. The strongest grilse can be distinguished from a sea trout,
evidence that this particular trout is merely In the salmon there are ten to twelve scales
a common brown trout veiling his identity, present, along an oblique line running
is that the young of the Great Lake trout forward from the root of the adipose fin
do not exist.
to the lateral line the line down each side
A Loch Leven trout, if removed from of a fish where every scale is perforated
the deep water of Loch Leven, again reverts with a vent-hole. In the sea trout, the
to his brown trout garb, and his silvery coat scales number fourteen.
with its black cross marks disappears.
The char is a near relative of the trout.
The gillaroo of Ireland has large brilliant In Great Britain it is found mainly in
red spots on a flashing golden body. The the Lake District, and particularly in Lake
THE PAGEANT OF NATURE
Windermere, though char exist in certain conspicuous than their companions, except
deep lakes in Scotland and Ireland. In when seen against a perfectly uniformly
my under-water tanks I have tried to shaded background. Such camouflage, of
photograph this fish; but the char is a course, is seldom, if ever, met with under
delicate fish, and the illustration shown natural conditions in the sea.
does not really represent it at its best. It Unlike the salmon and the sea trout at
is impossible to do justice to its brilliant home, the rainbow trout spawns not in
hues except in a colour plate. In appear- the autumn, but in the spring. A few
ance it is absolutely brilliant ; the back rainbows which I had under observation
down to the lateral line the line that can be spawned in May. Trout are supposed not
seen on any fish, which is due to perforated to feed when they are spawning, but these
holes through the scales along the middle rainbows when resting during their spawn-
of the body is of dark green. This dark ing operations were always ready to feed.
,.,.,,,, j - ^^.^^^^,. J ^__^ MM ^, On one occasion I threw no
fewer than fifty meal-worms,
one after another, to the trout,
and not one of the worms
was allowed to reach the
bottom. Indeed, the relish
with which these titbits was
met was as keen at the last
throw-in as at the first.
Other members of the salmon
family are the brook trout of
America, and the graylings,
which are well-known in
British and Canadian waters.
Both are fine sporting fish ;
the former is a char, and in
America holds a position
similar to that of the brown
The Char, a near relative of the trout, is a fish of
brilliant hues, which it is impossible to do justice to in
an ordinary photographic plate. Its beauty of coloration
is an unforgettable memory to the student of fish life, or
the lucky angler.
green gradually merges into a rich crimson
trout in Britain. Attempts to
introduce the brook trout into
England have met with a
certain amount of success in
a few deep ponds and lakes.
Last, but not least, there is the very
which covers the under-part, and on the engaging group of the " white fishes " of
green sides are numerous dark red spots. North America. These differ from other
The char is a gregarious fish and swims salmonoids in having large scales and
in shoals. In the autumn, when they delicately shaped mouths. The Irish pollan
come to the shallows from the deep waters is the best-known representative of this
in which they usually dwell in order to group in home waters. It should be
spawn, they are netted in great quantities, kept in mind that in America the term
and appear on the table as " potted char." " white fishes " applies to these large-
The rainbow trout is a native of the scaled salmonoids, in Britain it refers to
Pacific coast of America, and is a fish the roach, rudd, dace and other members
with which most people are familiar, of the silvery section of the carp family.
One might imagine that its prominent Britain is looked upon as the home of the
black spots and marks over the back and brown trout, and in all parts of the world
sides down to the lateral line, would render waters have been stocked with British trout
it conspicuous on all occasions. On the ova. In transit, incubation is checked by cold;
contrary, the rainbow and Loch Leven on arrival the temperature is very gradually
trout, which I have watched swimming in raised, and then the ova are hurried up
my pond with roach and dace, are less country.
By-ways of Plant Life
A grain of wheat, highly
magnified, showing tuft of
hairs which collect moisture.
Shows the cleft which forms
a sort of irrigation canal
leading from the tuft of
hairs to the germinating
Showing the " hump," beneath
which lies the embryo wheat
4,-HOW A GRAIN OF WHEAT
By HAROLD BASTIN
With photographs by the Author
OW does a grain of wheat grow ? favourable conditions gives evidence of its
presence in the phenomena that we term
" growth " and " development." But no-
In the last resort, this question
remains unanswerable. Hidden in-
visibly in the germ there is a " some- body has an idea, even vague and remote,
thing " that we call " life," which under of what this " life " really is. Yet a grain
On the second day of germi-
nation the skin above the
embryo is ruptured.
On the third day the primary
root appears wrapped in its
By the fifth day the sheath
is split and the primary
shoot and root are exposed,
THE PAGEANT OF NATURE
This shows the root-tip
further magnified. It is
hairy, semi-liquid at the
tip, and highly sensitive.
On the sixth day the
first pair of "adven-
titious" roots appear.
kind of vital legacy,
after generation, from
its remote ancestral
past. It is with the
immediate " how "
of this * race
memory " that the
If we examine a
grain of wheat ,
separated from an
sample, we see that it is spindle-shaped, with
a cleft or channel on one side, and a tuft of
silvery hairs at one extremity. Exposed to
, the influence of moisture, the grain swells,
until all the wrinkles in its skin are smoothed
away. Looking now at what we may call
the " obverse " side of the grain, we
notice again the tuft of hairs at one ex-
tremity, and at the other a sort of boss,
or hump, bounded by a depressed area,
or ditch. This hump will shortly call for
our undivided attention. Beneath it lies
the embryo, whence will issue the living
wheat plant. For the moment, however,
it will suffice to note that one extremity
of the hump that nearest to the hairy end
of the grain is termed (because of what
of wheat, in lies beneath it) the " plumule," or young
common with all shoot ; while the other extremity, for a
other livings like reason, is known as the " radicle," or
things that we young root.
know, is largely Turning the grain over and examining
governed in its its reverse side, we still notice the tuft
growth by a sort of hairs ; we see, too, that the cleft or
of race memory, channel originates among these hairs. It
fixed code of is, in fact, a kind of irrigation canal, which
procedure call conveys the moisture collected by the hairs
it what you will to the germinating point, the radicle of
that passes which is seen protruding from beneath,
mysteriously In this way the young root and the young
onward., like a shoot are kept constantly moistened through-
out the whole period of their early
It is important to realize that
the major portion of a grain of
wheat consists of a store of nourish-
ment destined to support the young
plant during its first struggle for
existence, and until it is sufficiently
established to obtain food for itself
from the surrounding elements.
This store is called the " albumen,"
and is quite distinct from the
" embryo," with its plumule and
By the seventh day the three roots are
burrowing into the soil, and the "plu-
mule," or young shoot, begins to grow.
BY-WAYS OF PLANT LIFE
radicle. The albumen, in fact, resembles Now let us pay special attention to
in its purpose the yolk-bag which is attached the primary root. The fact of its rapid
to and nourishes the young chick prior to growth, seems to indicate its importance,
its escape from the egg-shell. Its special duty is to supply the increasing
The conditions necessary if a wheat demand for moisture that the germinating
grain is to germinate are moisture, warmth, embryo is making. It must procure, more-
and the presence of oxygen. Oxygen is in over, certain chemicals in solution which
the air which fills the crevices between the are required for building up the living
particles of soil which surround the grain ;
moisture is absorbed both from the air
and from the soil. Sach's experiments
show that wheat begins to germinate
below 5 Centigrade say at about 40
Fahrenheit. But while germination may
commence at this point, its progress will be
slow, unless the temperature rises consider-
ably. It is in the warm days of early spring
that the young wheat plant thrives best.
The detailed particulars which follow
relate to an experiment which occupied
some 468 consecutive hours, with a tem-
perature which varied between 38 and 60
Fahrenheit. This period covered the whole
early history of the developing grain
from the time when it was first placed
upon wet sand, to the time when the first
folial leaf was fully expanded..
At noon on the second day twenty-
four hours after contact with moisture
the skin above the embryo was seen to
have ruptured, leaving a slit reaching from
end to end of the hump. Noon of the
third day saw a white point protruding
really the primary root wrapped in its
sheath. On the fifth day, at noon, the
whole of this sheath was exposed to view,
the outer skin was forced aside, while
the tips of the young root and the young
shoot were emerging from opposite ends
of the sheath.
At this point it is often noticeable that
the plumule is somewhat more advanced
than the radicle. The gain, however, is
short lived ; for the next important stage, cell-tissue of the plant which is to be. So
reached about noon of the sixth day, leaves the primary root burrows down into the soil,
the young shoot much as it was, while the and develops root-hairs delicate white
young root has extended in a surprisingly filaments which spread out at right angles
rapid manner. Moreover, we notice that to the root itself. These hairs assist in
the tips of two other roots have made the search for moisture ; also, by their
their appearance the first pair of " ad- ramification among the minute particles
ventitious " roots, as they are called ; and of soil, they must add materially to the
we begin to realize, perhaps for the first holding powers of the root an important
time, that the development of a young function in view of wind, or heavy rain,
wheat plant is a complex business, and that which may at any moment strain the
we have by no means s >en the end of it. anchorage of the tiny plant.
noon on the twelfth da Y the plumule is
growing well, and a second pair- of adventitious
THE PAGEANT OF NATURE
the fifteenth day the first green leaf
breaks through its sheath.
The most interesting part of the root,
however, is its tip. This is semi-liquid and
transparent ; yet it exhibits an exquisite
sensitiveness which enables it to avoid
destruction, or threatened injury feeling
its way between the particles of soil, or
round impenetrable obstacles. One is
tempted to endow it in imagination with a
kind of intelligence ! Indeed, Charles
Darwin likened a radicle to a burrowing
animal, such as a mole, when he described
its circumvolutions in search of suitable
soil, and its return, after each interruption,
to a downward course. Furthermore, the
root-tip is gifted with a remarkable power
of selection. It takes up from the moisture
in the soil such chemicals as it needs,
and leaves others for which it has no use !
If, for example, we plant a pea and a grain
of wheat in the same pot of soil, the root-
tip of the former will search for and absorb
the calcareous matter that the water of
the soil holds in solution. But the root-
tip of the wheat rejects this, and appro-
priates all the silex, or flinty matter, that
it can get. Because of the building of
this silex into the living stem of the wheat
plant the straw is rendered sufficiently
strong to support the ear and to with-
stand wind-pressure. It is said that there
is enough silex in a well-grown wheat
straw to make a bead of glass, when melted
with potash with the aid of a blow-pipe !
The pea, on the contrary, being one of
those plants which clamber over and
support themselves upon other vegetation,
does not need silex to strengthen its stems,
and so does not take it from the moisture
in the soil.
Thus the primary root-tip of the baby
wheat plant works its way among the
particles of soil, generally with a downward
tendency, but turning aside from obstacles
in its path, or moving hither and thither
in search of moisture and such chemical
substances as it may need. Moreover, the
primary root is not left to labour alone.
We have already seen the formation of
two adventitious root-sheaths ; and from
these issue, and pass down into the soil,
the first pair of adventitious roots, which
soon produce root-hairs, and exhibit all
the characters which we have already noted
in the primary root. This was the condition
of the young plant at noon on the seventh
day, the temperature then being 50 F.
It will be observed that the plumule has
On the sixteenth day the leaf had almost
freed itself from the sheath.
By noon on the twentieth day the young
wheat plant was an accomplished fact.
THE PAGEANT OF NATURE
made comparatively little growth so far. soil to augment the labours of its five
But as the three root-tips continue to work older brethren. Meantime the develop-
their way into the soil, the young plant ment of the leaf was slowed down. But
begins to feel its power if we may so by noon on the twentieth day the young
express it and the pale yellow plumule wheat plant was an accomplished fact,
makes more rapid growth.
Strictly speaking, it is not
a leaf, although it does
some of the work of a leaf ;
its chief office is to protect
the delicate first green leaf.
Even now this leaf lies
within, complete in every
detail ; but the status of
the plant is not yet suffi- .
ciently assured to warrant
its production. So the
plumule moves slowly up-
ward, and the roots con-
tinue to burrow more
deeply into the soil.
At noon on the twelfth
day there is another change
to note. The tiny plant is
about to send out a second
pair of adventitious roots.
The sheaths make their
appearance, the root-tips
emerge and commence
their journey downward
into the soil. Thus, by
noon on the fifteenth day,
our baby plant has a
system of five vigorous
roots, each endowed with
individual powers of selec-
tion, but all labouring for
the benefit of the one
It is at this stage that
the first green leaf breaks
through its protecting
sheath. Hour, by hour it
reaches upward towards
the light ; hour by hour
the faithful roots burrow,
like moles, into the dark,
Two matured and well-developed
ears of wheat. Owing to the
fortuitous circumstances of the
wheat plant's growth, difficulty
to obtain symmetrical photo-
graphs was experienced, yet in
the results it was found that
the principle of growth, as
described, had not been de-
parted from in the smallest
with a root system of six
units and a perfectly ex-
panded folial leaf.
These notes, and the
photographs which illus-
trate them, convey an
impression of symmetrical
growth which must now
be dispelled. From the
first, and although it is
manifestly dominated in
no small degree by the
" race memory " to which
reference has already been
made, the tiny wheat plant
shows infinite powers of
adapting itself to circum-
stances. Thrown upon the
bare furrow and washed
into the soil by rain, it is
surrounded by innumer-
able particles varying in
size from sand grains to
large stones. Among and
around these the root-tips
and plumule must find
their way, the former
downward, the latter up-
ward, no matter how
tortuous the course may
be. Moreover, it is un-
likely that the grain will
fall exactly in the position
necessary for straight-
forward growth. So that
the baby wheat plant of
a few days old has
generally twisted itself into
a confused tangle below
the surface of the soil. A
careful examination, how-
ever, will show that it has
moist soil. At noon on the sixteenth day the not departed in the smallest detail from the
leaf had almost freed itself from the sheath, principle of growth which has just been
but it was not wholly expanded. Then described. Yet so sensitive are the root-
as if the baby plant still mistrusted its tips, and so ready are they to turn from any
powers to make good its bold adventure obstacle, that even under ideal conditions
a sixth root-sheath was hastily formed considerable difficulty was experienced in
at the base of the plumule, and a sixth obtaining plants sufficiently symmetrical
adventitious root passed downward into the in growth to make good photographs.
How the Reptiles Live
rhoto: M. H. Crawford.
The Glass-snake (Ophiosaurus], or Legless Lizard, has retained a pair of slender stumps
to represent each pair of limbs. In the illustration the skin-flaps of both fore- and
hind-legs are seen.
3.-A BRITISH LEGLESS LIZARD: THE
SLOWWORM OR " BLINDWORM "
By P. CHALMERS MITCHELL, C.B.E., D.Sc., LL.D., F.R.S.
WHY should animals once blessed
with four legs give them up ? That
is certainly what has happened in
the case of the slowworm, the only British
legless lizard. The course of evolution
often seems to have been progress backwards,
the degeneration and then the partial and
even complete loss of an organ once useful,
but become either unnecessary or an actual
encumbrance. The ancestors of man and
the higher apes certainly used to have tails,
but man, like the gorilla and the chimpanzee,
the orang-utan and the gibbon, have all lost
them. In a great many of the other groups
of baboons and monkeys there are some
species which have the tail reduced to a
stump or not visible at all. If they take
to living on the ground more than in trees,
the tail loses its chief use.
I do not know if lizards suffer from in-
growing toe-nails, or cold feet, but certainly
a good many different kinds, especially
those which take to living in holes, or in