Celebrating 18 Years on the Web
TODAY IN SCIENCE HISTORY ®
Find science on or your birthday

Today in Science History - Quickie Quiz
Who said: “As far as the laws of mathematics refer to reality, they are not certain; and as far as they are certain, they do not refer to reality.”
more quiz questions >>
Home > Category Index for Science Quotations > Category Index P > Category: Propagation

Propagation Quotes (9 quotes)

In order that an inventory of plants may be begun and a classification of them correctly established, we must try to discover criteria of some sort for distinguishing what are called “species”. After a long and considerable investigation, no surer criterion for determining species had occurred to me than distinguishing features that perpetuate themselves in propagation from seed. Thus, no matter what variations occur in the individuals or the species, if they spring from the seed of one and the same plant, they are accidental variations and not such as to distinguish a species. For these variations do not perpetuate themselves in subsequent seeding. Thus, for example, we do not regard caryophylli with full or multiple blossoms as a species distinct from caryophylli with single blossoms, because the former owe their origin to the seed of the latter and if the former are sown from their own seed, they once more produce single-blossom caryophylli. But variations that never have as their source seed from one and the same species may finally be regarded as distinct species. Or, if you make a comparison between any two plants, plants which never spring from each other's seed and never, when their seed is sown, are transmuted one into the other, these plants finally are distinct species. For it is just as in animals: a difference in sex is not enough to prove a difference of species, because each sex is derived from the same seed as far as species is concerned and not infrequently from the same parents; no matter how many and how striking may be the accidental differences between them; no other proof that bull and cow, man and woman belong to the same species is required than the fact that both very frequently spring from the same parents or the same mother. Likewise in the case of plants, there is no surer index of identity of species than that of origin from the seed of one and the same plant, whether it is a matter of individuals or species. For animals that differ in species preserve their distinct species permanently; one species never springs from the seed of another nor vice versa.
John Ray
Historia Plantarum (1686), Vol. 1, 40. Trans. Edmund Silk. Quoted in Barbara G. Beddall, 'Historical Notes on Avian Classification', Systematic Zoology (1957), 6, 133-4.
Science quotes on:  |  Accident (58)  |  Animal (325)  |  Blossom (10)  |  Bull (2)  |  Cow (27)  |  Criterion (11)  |  Difference (214)  |  Distinct (31)  |  Distinguishing (14)  |  Individual (185)  |  Inventory (7)  |  Investigation (124)  |  Likewise (2)  |  Man (348)  |  Mother (66)  |  Multiple (9)  |  Parent (42)  |  Permanence (15)  |  Perpetuation (3)  |  Plant (182)  |  Production (107)  |  Seed (57)  |  Sex (48)  |  Single (88)  |  Species (198)  |  Variation (52)  |  Woman (98)

Life was born and propagates itself on the earth as a solitary pulsation.
In Teilhard de Chardin and Sara Appleton-Weber (trans.), The Human Phenomenon (1999, 2003), 60. Originally published in French as Le Phιnomene Humain (1955).
Science quotes on:  |  Birth (87)  |  Earth (582)  |  Life (993)  |  Pulsation (3)  |  Solitary (13)

My theory of electrical forces is that they are called into play in insulating media by slight electric displacements, which put certain small portions of the medium into a state of distortion which, being resisted by the elasticity of the medium, produces an electromotive force ... I suppose the elasticity of the sphere to react on the electrical matter surrounding it, and press it downwards.
From the determination by Kohlrausch and Weber of the numerical relation between the statical and magnetic effects of electricity, I have determined the elasticity of the medium in air, and assuming that it is the same with the luminiferous ether I have determined the velocity of propagation of transverse vibrations.
The result is
193088 miles per second
(deduced from electrical & magnetic experiments).
Fizeau has determined the velocity of light
= 193118 miles per second
by direct experiment.
This coincidence is not merely numerical. I worked out the formulae in the country, before seeing Webers [sic] number, which is in millimetres, and I think we have now strong reason to believe, whether my theory is a fact or not, that the luminiferous and the electromagnetic medium are one.
Letter to Michael Faraday (19 Oct 1861). In P. M. Harman (ed.), The Scientific Letters and Papers of James Clerk Maxwell (1990), Vol. 1, 1846-1862, 684-6.
Science quotes on:  |  Calculation (68)  |  Electromagnetism (17)  |  Ether (24)  |  Experiment (548)  |  Formula (51)  |  Friedrich Wilhelm Georg Kohlrausch (2)  |  Light Wave (2)  |  Speed Of Light (14)  |  Theory (585)  |  Vibration (13)

One of the grandest generalizations formulated by modern biological science is that of the continuity of life; the protoplasmic activity within each living body now on earth has continued without cessation from the remote beginnings of life on our planet, and from that period until the present no single organism has ever arisen save in the form of a bit of living protoplasm detached from a pre-existing portion; the eternal flame of life once kindled upon this earth has passed from organism to organism, and is still, going on existing and propagating, incarnated within the myriad animal and plant forms of everyday life.
In History of the Human Body (1919), 1.
Science quotes on:  |  Activity (101)  |  Animal (325)  |  Arise (35)  |  Beginning (115)  |  Biology (158)  |  Cessation (10)  |  Continuation (19)  |  Continuity (23)  |  Detach (2)  |  Earth (582)  |  Eternal (48)  |  Evolution (500)  |  Existence (265)  |  Form (223)  |  Formulation (20)  |  Generalization (26)  |  Incarnation (3)  |  Kindled (2)  |  Life (993)  |  Living Body (2)  |  Myriad (20)  |  Organism (144)  |  Planet (237)  |  Plant (182)  |  Protoplasm (12)

That many very remarkable change and involuntary motions are sudden produced in the body by various affections of the mind, is undeniably evinced from a number of facts. Thus fear often causes a sudden and uncommon flow of pale urine. Looking much at one troubled with sore eyes, has sometimes affected the spectator with the same disease.—Certain sounds cause a shivering over the whole body.—The noise of a bagpipe has raised in some persons an inclination to make urine.—The sudden appearance of any frightful object, will, in delicate people, cause an uncommon palpitation of the heart.—The sight of an epileptic person agitated with convulsions, has brought on an epilepsy; and yawning is so very catching, as frequently to be propagated through whole companies.
In An Essay on the Vital and Other Involuntary Motions of Animals (1751), 253-254.
Science quotes on:  |  Change (324)  |  Convulsion (5)  |  Disease (261)  |  Epilepsy (3)  |  Fear (124)  |  Fright (5)  |  Heart (125)  |  Involuntary (2)  |  Motion (135)  |  Urine (9)  |  Yawn (2)

The velocity of light is one of the most important of the fundamental constants of Nature. Its measurement by Foucault and Fizeau gave as the result a speed greater in air than in water, thus deciding in favor of the undulatory and against the corpuscular theory. Again, the comparison of the electrostatic and the electromagnetic units gives as an experimental result a value remarkably close to the velocity of light–a result which justified Maxwell in concluding that light is the propagation of an electromagnetic disturbance. Finally, the principle of relativity gives the velocity of light a still greater importance, since one of its fundamental postulates is the constancy of this velocity under all possible conditions.
Studies in Optics (1927), 120.
Science quotes on:  |  Air (171)  |  Conclusion (124)  |  Condition (130)  |  Constancy (4)  |  Constant (43)  |  Corpuscle (8)  |  Electromagnetic (2)  |  Electrostatic (4)  |  Experiment (548)  |  Jean-Bernard-Lιon Foucault (3)  |  Fundamental (124)  |  Importance (186)  |  James Clerk Maxwell (75)  |  Measurement (149)  |  Postulate (23)  |  Principle (232)  |  Relativity (51)  |  Result (267)  |  Speed Of Light (14)  |  Theory (585)  |  Unit (25)  |  Water (264)  |  Wave (58)

There is, it appears, a conspiracy of scientists afoot. Their purpose is to break down religion, propagate immorality, and so reduce mankind to the level of brutes. They are the sworn and sinister agents of Beelzebub, who yearns to conquer the world, and has his eye especially upon Tennessee.
[Report on the Scopes Monkey Trial.]
Baltimore Evening Sun (11 Jul 1925). In H.L. Mencken, S. T. Joshi (Ed.), H.L. Mencken on Religion (2002), 178.
Science quotes on:  |  Agent (28)  |  Beelzebub (2)  |  Break (41)  |  Brute (13)  |  Conquer (16)  |  Conspiracy (4)  |  Eye (190)  |  Immorality (4)  |  Level (57)  |  Mankind (217)  |  Purpose (145)  |  Reduction (37)  |  Religion (214)  |  Scientist (459)  |  Scopes Monkey Trial (6)  |  Sinister (8)  |  Swear (3)  |  Tennessee (3)  |  World (746)  |  Yearn (9)

This is the patent-age of new inventions
For killing bodies, and for saving souls,
All propagated with the best intentions;
Sir Humphrey Davy's lantern, by which coals
Are safely mined for in the mode he mentions,
Tombuctoo travels, voyages to the Poles,
Are ways to benefit mankind, as true,
Perhaps, as shooting them at Waterloo.
Don Juan (1819, 1858), Canto I, CXXXII, 36. Although aware of scientific inventions, the poet seemed to view them with suspicion. Davy invented his safety lamp in 1803. Sir W.E. Parry made a voyage to the Arctic Regions (4 Apr to 18 Nov 1818).
Science quotes on:  |  Age (146)  |  Benefit (58)  |  Best (143)  |  Body (206)  |  Coal (42)  |  Sir Humphry Davy (45)  |  Intention (26)  |  Invention (287)  |  Killing (14)  |  Lantern (5)  |  Mankind (217)  |  Mining (11)  |  New (380)  |  Patent (23)  |  Pole (15)  |  Safety Lamp (3)  |  Saving (20)  |  Shooting (6)  |  Soul (151)  |  Travel (55)

We are machines built by DNA whose purpose is to make more copies of the same DNA. ... This is exactly what we are for. We are machines for propagating DNA, and the propagation of DNA is a self-sustaining process. It is every living object's sole reason for living.
Royal Institution Christmas Lecture, 'The Ultraviolet Garden', (No. 4, 1991). Quoted in Vinoth Ramachandra, Subverting Global Myths: Theology and the Public Issues Shaping our World (2008), 187.
Science quotes on:  |  Copy (16)  |  DNA (67)  |  Life (993)  |  Machine (136)  |  Process (210)  |  Purpose (145)  |  Reason (343)  |  Reproduction (60)  |  Self-Sustaining (3)


Carl Sagan Thumbnail In science it often happens that scientists say, 'You know that's a really good argument; my position is mistaken,' and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion. (1987) -- Carl Sagan
Quotations by: • Albert Einstein • Isaac Newton • Lord Kelvin • Charles Darwin • Srinivasa Ramanujan • Carl Sagan • Florence Nightingale • Thomas Edison • Aristotle • Marie Curie • Benjamin Franklin • Winston Churchill • Galileo Galilei • Sigmund Freud • Robert Bunsen • Louis Pasteur • Theodore Roosevelt • Abraham Lincoln • Ronald Reagan • Leonardo DaVinci • Michio Kaku • Karl Popper • Johann Goethe • Robert Oppenheimer • Charles Kettering  ... (more people)

Quotations about: • Atomic  Bomb • Biology • Chemistry • Deforestation • Engineering • Anatomy • Astronomy • Bacteria • Biochemistry • Botany • Conservation • Dinosaur • Environment • Fractal • Genetics • Geology • History of Science • Invention • Jupiter • Knowledge • Love • Mathematics • Measurement • Medicine • Natural Resource • Organic Chemistry • Physics • Physician • Quantum Theory • Research • Science and Art • Teacher • Technology • Universe • Volcano • Virus • Wind Power • Women Scientists • X-Rays • Youth • Zoology  ... (more topics)
Sitewide search within all Today In Science History pages:
Visit our Science and Scientist Quotations index for more Science Quotes from archaeologists, biologists, chemists, geologists, inventors and inventions, mathematicians, physicists, pioneers in medicine, science events and technology.

Names index: | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |

Categories index: | 1 | 2 | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |

- 100 -
Sophie Germain
Gertrude Elion
Ernest Rutherford
James Chadwick
Marcel Proust
William Harvey
Johann Goethe
John Keynes
Carl Gauss
Paul Feyerabend
- 90 -
Antoine Lavoisier
Lise Meitner
Charles Babbage
Ibn Khaldun
Euclid
Ralph Emerson
Robert Bunsen
Frederick Banting
Andre Ampere
Winston Churchill
- 80 -
John Locke
Bronislaw Malinowski
Bible
Thomas Huxley
Alessandro Volta
Erwin Schrodinger
Wilhelm Roentgen
Louis Pasteur
Bertrand Russell
Jean Lamarck
- 70 -
Samuel Morse
John Wheeler
Nicolaus Copernicus
Robert Fulton
Pierre Laplace
Humphry Davy
Thomas Edison
Lord Kelvin
Theodore Roosevelt
Carolus Linnaeus
- 60 -
Francis Galton
Linus Pauling
Immanuel Kant
Martin Fischer
Robert Boyle
Karl Popper
Paul Dirac
Avicenna
James Watson
William Shakespeare
- 50 -
Stephen Hawking
Niels Bohr
Nikola Tesla
Rachel Carson
Max Planck
Henry Adams
Richard Dawkins
Werner Heisenberg
Alfred Wegener
John Dalton
- 40 -
Pierre Fermat
Edward Wilson
Johannes Kepler
Gustave Eiffel
Giordano Bruno
JJ Thomson
Thomas Kuhn
Leonardo DaVinci
Archimedes
David Hume
- 30 -
Andreas Vesalius
Rudolf Virchow
Richard Feynman
James Hutton
Alexander Fleming
Emile Durkheim
Benjamin Franklin
Robert Oppenheimer
Robert Hooke
Charles Kettering
- 20 -
Carl Sagan
James Maxwell
Marie Curie
Rene Descartes
Francis Crick
Hippocrates
Michael Faraday
Srinivasa Ramanujan
Francis Bacon
Galileo Galilei
- 10 -
Aristotle
John Watson
Rosalind Franklin
Michio Kaku
Isaac Asimov
Charles Darwin
Sigmund Freud
Albert Einstein
Florence Nightingale
Isaac Newton



who invites your feedback
Thank you for sharing.
Today in Science History
Sign up for Newsletter
with quiz, quotes and more.