United States or Israel ? Vote for the TOP Country of the Week !
But if the Radiolaria and Diatoms are thus rained upon the bottom of the sea, from the superficial layer of its waters in which they pass their lives, it is obviously possible that the Globigerinoe may be similarly derived; and if they were so, it would be much more easy to understand how they obtain their supply of food than it is at present.
Among protophytes it needs but to think of the multitudinous varieties of diatoms and desmids, with their elaborately-constructed coverings; or of the definite methods of growth and multiplication among such simple Algæ as the Conjugatæ; to see that most of their distinctive characters are due to inherited constitutions, which have been slowly moulded by survival of the fittest to this or that mode of life.
One Gemiasma. 4th specimen. None. 5th specimen. Skin scraped showed no plants. 6th specimen. Urine; amyloid bodies; spores; no sporangia. United States Magazine store grounds. Observation 1. Margin of Eastern Branch River. Substance from decaying part of a water plant. Oscillatoriaceae. Diatoms. Anguillula. Chytridium. Dirt. No Gemiasma. Observation 2. Moist soil.
These tubes will be found very useful for collecting and concentrating into a small bulk the sediment contained in any liquid, whether it be composed of urinary deposits, diatoms in process of being cleaned, or any thing of like nature; and, as the parts are all of glass, the strongest acids may be used, excepting, of course, hydrofluoric acid, without harm to the tubes.
Now, it is remarkable that these microscopic shells of Diatoms are not unfrequently found in the ejections of volcanoes; while it is generally supposed that, in the case of those situated near the sea, eruptions are caused by the formation of explosive steam consequent on the access of sea-water to the reservoirs of molten lava lying underground.
This goes on very rapidly, and in this plant each new cell separates as it is formed, and the free diatoms move about quite actively in the water. If you consider for a moment, you will see that, as the new valves always fit into the old ones, each must be smaller than the last, and so there comes a time when the valves have become too small to go on increasing. Then the plant must begin afresh.
Many distinctions founded on this belief have since had to be abandoned. Species of algae belonging to the well-preserved group of the diatoms, are said to have remained unchanged from the Carboniferous period up to the present time.
One finds, not unfrequently, groups of three and four closely resembling Protococcus. Starch is invariably present; the wall is true plant-cellulose, yielding a magnificent blue with iodine and sulphuric acid, and the yellow coloring matter is identical with that of diatoms, and yields the same greenish residue after treatment with alcohol.
And very soon he was hard at work in his habitual strenuous fashion, at these microscopic denizens of the way-side pool. It was on the third day of the diatoms that Hapley became aware of a novel addition to the local fauna. He was working late at the microscope, and the only light in the room was the brilliant little lamp with the special form of green shade.
This, when examined under the microscope, was found to consist almost entirely of the frustules of Diatoms, some of them wonderfully perfect in all the details of their ornament, and many of them broken up.
Word Of The Day