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absorbed active adapted Amoeba animal or plant animals and plants appear auricle bacteria blood vessels body bones brain buds called cambium carbon dioxid carpels cavity cell union cell wall centrosome characters chemical chlorophyll chromatin chromosomes colony conjugation contain cord developed digestive divides division ducts earthworm endoderm energy excreted fern fertilization fibers flagella flower force frog functions gametophyte germ plasm glands green plants growing heredity Hydra individual intestine known large number layer liquid living organism living things lymph machine male material membrane micronucleus microscopic minute motion mouth multicellular muscles nematocysts nerve nervous neurons nucleus offspring original ovary oxygen Pandorina Paramecium parasites passes photosynthesis pistil pollen posterior produced proteids prothallium protoplasm result root sexual sexual reproduction single cell species sperm spinal spores starch stem stomata structure substance tion tissues tube unicellular variations vertebra yeast
Page 353 - ... in the long run, to win in the contest. Hence the " fittest " in the long run will survive, while those less fitted to exist will be exterminated. " 5. Heredity. By the laws of heredity, individuals transmit to their offspring their own characters. Hence if one individual survives the struggle for existence by virtue of some special characteristic, it will transmit this characteristic to its offspring. The offspring will inherit it, and in the course of a few generations the only individuals...
Page 353 - 1. Overproduction. All animals and plants tend to multiply more rapidly than it is possible for them to continue to exist. More offspring are produced by even the slowest breeding animals and plants than can possibly find sustenance in the world. " 2. Struggle for existence. As a result of overproduction, the individuals that are born are engaged in a constant struggle with each other for the opportunity to live. This struggle is sometimes an active, sometimes a passive one; and sometimes it is...
Page 24 - Observations upon the generation, composition, and decomposition of animals and vegetable substances, London, 1749 ; Notes sur les Nouvelles decouvertes de Spallanzani, Paris, 1768.
Page iii - List price, 50 cents; mailing price, 55 cents THIS work is intended to serve as an introduction to the study of algebra, and is adapted to the needs of the seventh or eighth school year. It is arranged in harmony with the leading courses of study that include algebra in the curriculum of the grades. The relation of algebra to arithmetic is emphasized, the subject is treated topically, and each important point...
Page 372 - ... reader in becoming familiar with the technical terms applied to the organs or parts of the flower which it is desirable to understand, and by means of which he will soon learn to distinguish the different species more readily. In giving the scientific names, the first word that occurs in parenthesis is the name of the genus ; the second, that of the species ; as, for instance, in Timothy (Phleum pratense), Phleum is the generic name, pratense the specific.
Page 188 - This sinus opens into the right auricle, which thus receives all the blood which flows back to the heart from all parts of the body, except the lungs. The blood from the lungs empties into the left auricle by two small veins, one from each lung; Fig.
Page 375 - The classification accepted by science is ever undergoing changes, as a more complete knowledge of relations is obtained, and the classification accepted to-day is different in many respects from that adopted a generation ago. In turn, the classification used to-day will doubtless be modified by future study, until it becomes practically perfect.
Page 377 - PLATYHELMINTHES: flat, unsegmented worms. Class I. Cestoda: the tapeworms. Class II. Trematoda: the flukes. Class III. Turbellaria: the planarians. Phylum V. NEMATHELMINTHES : round, unsegmented worms: round worms, threadworms. Phylum VI. MOLLUSCOIDEA. Class I. Polyzoa: sea-mats, corallines. Class II. Brachiopoda: lamp-shells. Phylum VII. ANNULATA: the segmented worms. Class I.