The Science-history of the Universe, Volumen6Current Literature Publishing Company, 1909 |
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Términos y frases comunes
abundant active adapted Africa Age of Reptiles Algæ altho ancestors ancient animals Ants appear Australia bees birds body botanists botany Cæsalpino carnivorous carpel cells chlorophyll color continents coral crustaceans Dinosaurs early eggs elephant evolution extinct feed feet females ferns fish flower fossil Fungi fungus geological gigantic growth habits higher hind horses important inhabit insects jaws kinds known land larger larva larvæ leaf leaves less limbs Linnæus living mammals marine Marsupials metamorphosis modern mollusks morphology Mosses natural nest North northern organs ovule plants pollen prey primitive protoplasm quadrupeds queen races regions reproduction rodents root seed sexual side skeleton smaller snakes South America species spiders spores sporophyte stamens starfish stem structure substance surface tail teeth terrestrial Tertiary Period Thylacine tion toes trees tropical tusks various vegetable vertebrates Wasps wings workers young
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Página 56 - Aphilanthops and Bembex, a number of individuals build close together, forming a colony. The nests may be made of mud, and attached for shelter under leaves, rocks, or eaves of buildings, or may be burrows hollowed out in the ground, in trees or in the stems of plants. The adult wasp lives upon fruit or nectar, but the young grub or larva must have animal food ; and here the parent wasp shows a rigid conservatism, each species providing the sort of food that has been approved by its family for generations,...
Página 272 - ... decided multiformity: there will result the comparatively integrated and comparatively differentiated Protophyta and Protozoa. The production of minute aggregates of physiological units being the first step, and the passage of such minute aggregates into more consolidated and more complex forms being the second step, it must naturally happen that all higher organic types, subsequently arising by further integrations and differentiations, will everywhere bear the impress of this earliest phase...
Página 208 - Species comprises all the individual plants which resemble each other sufficiently to make us conclude that they are all, or may have been all, descended from a common parent. These individuals may often differ from each other in many striking particulars, such as the colour of the flower, size of the leaf, etc., but these particulars are such as experience teaches us are liable to vary in the seedlings raised from one individual.
Página 206 - ... rocks. Whether the present species, which often resemble these, have arisen from them ; whether the great revolutions on the surface of the earth, which we read in the Book of Nature, contributed to these transitions — we know not. What we know is that from as early a time as the human race has left memorials of its existence upon the earth the separate species of plants have maintained the same properties invariably. To be sure, we frequently speak of the transitions and crossings of species...
Página 208 - Nature produces individuals and nothing more. . . . Species have no actual existence in nature. They are mental concepts and nothing more. . . . Species have been invented in order that we may refer to great numbers of individuals collectively.
Página 56 - When the egg-laying time arrives the female secures her prey, which she either kills or paralyzes, places it in the nest, lays the egg upon it, and then, in most cases, closes the hole and takes no further interest in it, going on to make new nests from day to day. In some genera the female maintains a longer connection with her offspring, not bringing all the provision at once but returning to feed the larva as it grows, and only leaving the nest permanently when the grub has spun its cocoon and...
Página 239 - ... indefinitely, thus forming thick carpets and masses. Bog mosses often completely fill up bogs or small ponds and lakes with a dense growth, which dies below and continues to grow above as long as the conditions are favorable. These quaking bogs or "mosses," as they are sometimes called, furnish very treacherous footing unless rendered firmer by other plants.
Página 308 - ... present time no evidence exists to show that the farm, garden or nursery has ever produced alterations which were strictly and continuously inheritable, or were present, except under environic conditions similar to those by which the alterations were produced, although vague statements and erroneous generalizations to the contrary are current. It is true of course that structural and physiological changes may be induced in a strain of plants in any generation, which may persist in a share to...
Página 190 - As the nature of plants," so begins Caesalpino's book, "possesses only that kind of soul by which they are nourished, grow, and produce their like, and they are therefore without sensation and motion in which the nature of animals consists, plants have accordingly need of a much smaller apparatus of organs than animals.
Página 44 - Finally, the monkish legends tell us that St. Francis Xavier, seeing a Mantis moving along in its solemn way, holding up its two forelegs as in the act of devotion, desired it to sing the praises of God, whereupon the insect carolled forth a fine canticle ! SOME SUGGESTIONS.