United States or Vanuatu ? Vote for the TOP Country of the Week !
The waves not only heap up broken coral, but they grind the coral into fine powder, and from this powder limestone rock is made, just as it is from the powdered shells of rhizopods.
We find, first, that the shells of pteropods and other surface Mollusca which are constantly falling on the bottom, are absent, or, if a few remain, they are brittle and yellow, and evidently decaying rapidly. These shells of Mollusca decompose more easily and disappear sooner than the smaller, and apparently more delicate, shells of rhizopods.
They can only be called organisms in so far as they are capable of exercising the organic phenomena of life, of nutrition, reproduction, sensation and movement." Verworn records an interesting instance of life and mind among the Rhizopods, a very low form of living thing.
"Not for me," said one of them, whose name is known wherever science is held in honor: "there must be no end of Rhizopods I have never studied."
Chalk cliffs and chalk layers extend from Ireland, through England and France, as far as to the Crimea. In the south of Russia they are said to be six hundred feet thick. Yet one cubic inch of chalk is calculated to hold the remains of more than one million rhizopods. How many countless millions upon millions must have gone to the whole structure! How long must the work of building up have lasted!
The animal is of the very simplest as well as the smallest kind. He has not even a mouth or a stomach but can take in food at any part of his body. These rhizopods live in the oceans in enormous numbers. Tens of millions are ever coming into existence, living out their tiny lives, dying, and sinking to the bottom.
For a long while they were believed to be living animals, like the rhizopods. Scientific men are now, however, pretty well agreed that they really are only vegetables or plants. The diatoms have each one a tiny shell or shield, not made of lime like the rhizopod-shells, but of flint. Some think that common flint may be formed of these tiny shells.
Water-built rocks are sometimes divided into two classes those which only contain occasional animal remains, and those which are more or less built up of the skeletons of animals. There are some exceedingly tiny creatures inhabiting the ocean, called Rhizopods.
They live in minute shells, the largest of which may be almost the size of a grain of wheat, but by far the greater number are invisible as shells without a microscope, and merely show as fine dust. The rhizopods are of different shapes, sometimes round, sometimes spiral, sometimes having only one cell, sometimes having several cells. In the latter case a separate animal lives in each cell.
Wallace had written Darwin's book under another name, and if these men had not written it, Haeckel surely would, for it was all packed away in his heart and head. As Darwin had studied and classified the Cirripedia, so would he write an essay on Rhizopods. Luck was with him luck is always with the man of purpose. He had an opportunity to travel through Italy as medical caretaker to a rich invalid.
Word Of The Day