Foundations of BiologyMacmillan, 1922 - 476 стор. |
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adapted alimentary canal animals and plants appear archegonia arise artery asexual Bacteria biology blastula body wall capillaries carbohydrates carbon dioxide carpels cavity cell division cell wall characteristic characters chemical chiefly chlorophyll chromatin chromosomes coelom complex Crayfish cytoplasm differentiation digestive dorsal duct Earthworm ectoderm embryo endoderm energy essentially evolution exhibit fact female Ferns fertilization filament Flowering Plants food materials function fundamental gametes gametophyte gastrula genes germ cells glands green plants growth higher Hydra individual inheritance intestine kidney known layer leaf living matter male Mammals membrane mesoderm metabolism micronuclei modified multicellular muscle nephridium nerve nitrogen nucleus organs oxygen pair Paramecium parent physiological plants and animals plasm pollen proteins protoplasm reproduction result root sexual simple somatic species sperm Sphaerella spinal spores sporophyte stem structure surface SYR SYR SYR tion tissues transformed tube types typical unicellular vacuole vascular vein ventral Vertebrates zygote
Популярні уривки
Сторінка 210 - But expectation is permissible where belief is not ; and if it were given me to look beyond the abyss of geologically recorded time to the still more remote period when the earth was passing through physical and chemical conditions, which it can no more see again than a man can recall his infancy, I should expect to be a witness of the evolution of living protoplasm from not living matter.
Сторінка 409 - It is interesting to contemplate a tangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth...
Сторінка 159 - I began to think whether there might not be a motion, as it were, in a circle. Now this I afterwards found to be true; and I finally saw that the blood, forced by the action of the left ventricle into the arteries, was distributed to the body at large, and its several parts, in the same manner as it is sent through the lungs, impelled by the right ventricle into the pulmonary artery, and that it then passed through the veins and along the vena caya, and so round to the left ventricle in the manner...
Сторінка 2 - The register of knowledge of fact is called history. Whereof there be two sorts: one called natural history; which is the history of such facts, or effects of nature, as have no dependence on man's will; such as are the histories of metals, plants, animals, regions, and the like. The other, is civil history; which is the history of the voluntary actions of men in commonwealths.
Сторінка 409 - Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one ; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have...
Сторінка 52 - The student of Nature wonders the more and is astonished the less, the more conversant he becomes with her operations ; but of all the perennial miracles she offers to his inspection, perhaps the most worthy of admiration is the development of a plant or of an animal from its embryo. Examine the recently laid egg of some common animal, such as a salamander or a newt. It is a minute spheroid in which the best microscope will reveal nothing but a structureless sac, enclosing a glairy fluid, holding...
Сторінка 374 - As many more individuals of each species are born than can possibly survive; and as, consequently, there is a frequently recurring struggle for existence, it follows that any being, if it vary however slightly in any manner profitable to itself, under the complex and sometimes varying conditions of life, will have a better chance of surviving, and thus be naturally selected. From the strong principle of inheritance, any selected variety will tend to propagate its new and modified form.
Сторінка 306 - No other environment consisting of primary constituents made up of other known elements, or lacking water and carbonic acid, could possess a like number of fit characteristics or such highly fit characteristics, or in any manner such great fitness to promote complexity, durability and active metabolism in the organic mechanism which we call life.
Сторінка 404 - The essentially simple idea is that the present is the child of the past, and the parent of the future.
Сторінка 409 - Variability from the indirect and direct action of the conditions of life, and from use and disuse; a Ratio of Increase so high as to lead to a Struggle for Life, and as a consequence to Natural Selection, entailing Divergence of Character and the Extinction of less improved forms. Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows.