00000445 |
Previous | 445 of 595 | Next |
|
small (250x250 max)
medium (500x500 max)
Large
Extra Large
large ( > 500x500)
Full Resolution
All (PDF)
|
402
LIFE.
To avoid the extremes of temperature, either the cold of winter or the
too great heat of summer, certain species of animals have also the resource
of burying themselves in the ground. The greater part of the insects pass
their existence as larvae under the bark of trees, under heaps of leaves, or
beneath the superficial strata of the earth. Some species of mollusks and
fish, several reptiles, and a few mammals, hide themselves also in the mud
of the lakes and marshes, or in burrows hollowed out beforehand. Thus
protected from the climate outdoors, the animals fall into a state of torpor, during which their life remains partially suspended; the temperature
of their bodies sometimes sinks to freezing-jpoint, and fish have even been
seen completely frozen, without this apparent death having prevented
their resuscitation later; respiration and circulation of the blood are
gradually slackened, and digestion ceases entirely; the organs, becoming temporarily useless, are restricted; even the intestinal parasites are
numbed with the animals upon which they live. This long period of
sleep is, however, a phenomenon which is found much more generally in
the vegetable world. For, in fact, all the plants of the frigid and polar
zones repose in the winter, and only live by their stems and roots; even
in warm countries, the plants present a remarkable periodicity in their existence.*
Although the privilege of locomotion permits a number of animals to
enlarge their domain considerably, the species do not the less remain subject to climatal conditions, and all have an area of habitation limited either toward the pole by the severity of the cold, or toward the equator by
too great heat. Each climate has its particular fauna, which, in order to
live and propagate itself easily, requires certain normal conditions of temperature and moisture. There are animals which can not quit the torrid
zone without perishing, or living an artificial life like most of those transported at a great expense to our zoological gardens; other species die if
they are taken from the northern countries, covered with ice during the
greater part of the year. The field-mouse seen by M. Martins on the Faulhorn, and certain animalculae, such as the Desoria nivalis and the Podura
hiemalis, have their dwelling in the snow, or on the ground covered by it.
On the other hand, certain rotifers exclusively inhabit thermal waters; a
scarabaeus, the Hydrobius orbicularis, lives in the sources of Hammam-
Meskoutine, the temperature of which is 131°. In the seas the whale
and various cetaceae are arrested by the warm waters of tropical latitudes as if by a barrier of flame, while the cachalot and the sea-cow swim
only in the tepid waters of the equatorial ocean.f In the same way the
coral insects are only seen in seas whose temperature is above 72° Fahrenheit ; at 60° they can still live, but without developing their branches.
The Gulf Stream, which carries into the northern seas the warm water
from the Antilles and Bahamas, carries also with it multitudes of southern species, which never stray either to the right or left into the colder
waters of the polar current. The two masses of water, flowing parallel
* See above, p. 364. f Maury, Geographic de la Mer.
| Title | The ocean, atmosphere, and life |
| Creator | Reclus, Elisée |
| Publisher | Harper |
| Place of Publication | New York |
| Date | 1873 |
| Language | eng |
| Type | Books/Pamphlets |
| Title | 00000445 |
| Type | Books/Pamphlets |
| Transcript | 402 LIFE. To avoid the extremes of temperature, either the cold of winter or the too great heat of summer, certain species of animals have also the resource of burying themselves in the ground. The greater part of the insects pass their existence as larvae under the bark of trees, under heaps of leaves, or beneath the superficial strata of the earth. Some species of mollusks and fish, several reptiles, and a few mammals, hide themselves also in the mud of the lakes and marshes, or in burrows hollowed out beforehand. Thus protected from the climate outdoors, the animals fall into a state of torpor, during which their life remains partially suspended; the temperature of their bodies sometimes sinks to freezing-jpoint, and fish have even been seen completely frozen, without this apparent death having prevented their resuscitation later; respiration and circulation of the blood are gradually slackened, and digestion ceases entirely; the organs, becoming temporarily useless, are restricted; even the intestinal parasites are numbed with the animals upon which they live. This long period of sleep is, however, a phenomenon which is found much more generally in the vegetable world. For, in fact, all the plants of the frigid and polar zones repose in the winter, and only live by their stems and roots; even in warm countries, the plants present a remarkable periodicity in their existence.* Although the privilege of locomotion permits a number of animals to enlarge their domain considerably, the species do not the less remain subject to climatal conditions, and all have an area of habitation limited either toward the pole by the severity of the cold, or toward the equator by too great heat. Each climate has its particular fauna, which, in order to live and propagate itself easily, requires certain normal conditions of temperature and moisture. There are animals which can not quit the torrid zone without perishing, or living an artificial life like most of those transported at a great expense to our zoological gardens; other species die if they are taken from the northern countries, covered with ice during the greater part of the year. The field-mouse seen by M. Martins on the Faulhorn, and certain animalculae, such as the Desoria nivalis and the Podura hiemalis, have their dwelling in the snow, or on the ground covered by it. On the other hand, certain rotifers exclusively inhabit thermal waters; a scarabaeus, the Hydrobius orbicularis, lives in the sources of Hammam- Meskoutine, the temperature of which is 131°. In the seas the whale and various cetaceae are arrested by the warm waters of tropical latitudes as if by a barrier of flame, while the cachalot and the sea-cow swim only in the tepid waters of the equatorial ocean.f In the same way the coral insects are only seen in seas whose temperature is above 72° Fahrenheit ; at 60° they can still live, but without developing their branches. The Gulf Stream, which carries into the northern seas the warm water from the Antilles and Bahamas, carries also with it multitudes of southern species, which never stray either to the right or left into the colder waters of the polar current. The two masses of water, flowing parallel * See above, p. 364. f Maury, Geographic de la Mer. |
|
|
|
|
|
|
| B |
|
| C |
|
| G |
|
| H |
|
| M |
|
| T |
|
| U |
|
| Y |
|
|
|
