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Jacques Loeb

Jacques Loeb is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Jacques Loeb rather than just read about it. In short: Jacques Loeb (; German: [løːp]; April 7, 1859 – February 11, 1924) was a German-born American physiologist and biologist. Biography Jacques Loeb, born Itzak, firstborn son of a Jewish family from the German Eifel region, was educated at the Friedrich Wilhelm University of Berlin, the Ludwig-Maximilians-Universität München, and the University of Strasbourg (M.D. 1884).

Jacques Loeb — main illustration
Jacques Loeb — illustration

Key takeaways

  • Jacques Loeb belongs to biology; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Jacques Loeb to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Jacques Loeb from memory before moving on to harder problems.

Reference excerpt

Jacques Loeb (; German: [løːp]; April 7, 1859 – February 11, 1924) was a German-born American physiologist and biologist.

Biography Jacques Loeb, born Itzak, firstborn son of a Jewish family from the German Eifel region, was educated at the Friedrich Wilhelm University of Berlin, the Ludwig-Maximilians-Universität München, and the University of Strasbourg (M.D. 1884). He took postgraduate courses at the University of Strasbourg and the Friedrich Wilhelm University of Berlin, and in 1886 became assistant at the physiological institute of the University of Würzburg, remaining there until 1888. In a similar capacity, he then went to the University of Strasbourg. During his vacations he pursued biological research, in Kiel in 1888, and in Naples in 1889 and 1890. Loeb first arrived in the United States in 1891 when he accepted a position at Bryn Mawr College. The College, however, provided insufficient facilities for his work, leading to his resignation. In 1892, he was called to the University of Chicago as assistant professor of physiology and experimental biology, becoming associate professor in 1895, and professor of physiology in 1899. John B. Watson (the "father of Behaviorism") attended Loeb's neurology classes at the University of Chicago. He was elected a member to the American Philosophical Society in 1899. In 1902, he was called to fill a similar chair at the University of California, Berkeley. Loeb was among the professors who had summer homes on "Professors' Row", near the sea cliffs in Carmel, California; John Fleming Wilson called Carmel Point "Point Loeb" after him. In 1910, Loeb moved to the Rockefeller Institute for Medical Research in New York, where he headed a new department. He remained at the Institute, now Rockefeller University, until his death. Loeb spent summers at the Marine Biological Laboratory in Woods Hole, Massachusetts, performing experiments on marine invertebrates. These included an experiment on artificial parthenogenesis. Loeb was able to switch the sea urchins' eggs to starting embryonic development without sperm. Modifications of the water in which the eggs were kept served as the stimulus for the development to begin. Later in 1918, Loeb established and became the first Editor of the Journal of General Physiology. Jacques Loeb became one of the most famous scientists in America, widely covered in newspapers and magazines, influencing other important individuals in the scientific world such as B.F. Skinner. He was the model for the character of Max Gottlieb in Sinclair Lewis's Pulitzer-winning novel Arrowsmith, the first great work of fiction to idealize and idolize pure science. Mark Twain also wrote an essay titled "Dr. Loeb's Incredible Discovery", urging the reader not to support a rigid consensus, but to instead be open to new scientific advances. Loeb was nominated many times for the Nobel Prize but never won. Dr. Loeb was an atheist.

Death "Whatever we may individually think of the ultimate conclusions which he drew from his investigations, there can be but one opinion of Loeb's immense serviceability as an investigator. With his departure from our midst an immense intellectual force has been taken from the world and his disciples and those who disagree with him alike are permanently impoverished by its loss." Prof. T. Brailsford Robertson (1926). He died of coronary artery disease while vacationing in Bermuda in 1924.

Research area The main subjects of Loeb's work were:

Animal tropisms and their relation to the instincts of animals Heteromorphosis, the replacement of an injured or removed organ by a different organ Toxic and antitoxic effects of ions Artificial parthenogenesis Hybridization of the eggs of sea-urchins by the sperm of starfish

Works Among Loeb's works the following may be mentioned:

Der Heliotropismus der Thiere und seine Uebereinstimmung mit dem Heliotropismus der Pflanzen, Würzburg: Verlag von Georg Hertz, 1890. Untersuchungen zur physiologischen Morphologie der Thiere, Würzburg: Verlag von Georg Hertz, 1891–1892. 2 vols., vol. 1: Ueber Heteromorphose, vol. 2: Organbildung und Wachsthum. Einleitung in die vergleichende Gehirnphysiologie und vergleichende Psychologie, Leipzig: J. A. Barth, 1899. English ed., Comparative physiology of the brain and comparative psychology, New York: Putnam, 1900. Studies in general physiology, Chicago: The University of Chicago Press, 1905. The dynamics of living matter, New York: Columbia University Press, 1906. The mechanistic conception of life: biological essays, Chicago: The University of Chicago Press, 1912; reprint, Cambridge, Mass.: Harvard University Press, 1964. Artificial parthenogenesis and fertilization, translated from German by W. O. Redman King, reviewed and edited by Loeb. Chicago: The University of Chicago Press, 1913. The organism as a whole, from a physicochemical viewpoint, New York: Putnam, 1916. Forced movements, tropisms, and animal conduct, Philadelphia: Lippincott, 1918. Proteins and the theory of colloidal behavior, New York: McGraw-Hill, 1922. The Mechanistic Conception of Life is Loeb's most famous and influential work. It contains English translations of some of his previous publications in German.

Family His younger brother Leo also immigrated to the United States where he became a noted pathologist.

References

Sources This article incorporates text from a publication now in the public domain: Singer, Isidore; et al., eds. (1901–1906). The Jewish Encyclopedia. New York: Funk & Wagnalls. {{cite encyclopedia}}: Missing or empty |title= (help)

External links

Jacques Loeb at The Embryo Project Encyclopedia. Loeb Family Tree Jacques Loeb at the Jewish Encyclopedia. Jacques Loeb at infoplease.com. National Academy of Sciences Biographical Memoir

Illustrations

Jacques Loeb illustration

Worked examples

Example 1 — a first encounter with Jacques Loeb

Start with the simplest possible case. Write down what Jacques Loeb claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Jacques Loeb before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Jacques Loeb ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Jacques Loeb

In research
Jacques Loeb appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Jacques Loeb in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Jacques Loeb is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1859 births, 1924 deaths, 19th-century German Jews, so understanding it makes those chapters shorter.
In everyday life
Look for Jacques Loeb outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Jacques Loeb in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Jacques Loeb means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Jacques Loeb out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Jacques Loeb in simple terms?

Jacques Loeb (; German: [løːp]; April 7, 1859 – February 11, 1924) was a German-born American physiologist and biologist. Biography Jacques Loeb, born Itzak, firstborn son of a Jewish family from the German Eifel region, was educated at the Friedrich Wilhelm University of Berlin, the Ludwig-Maximil…

Why does Jacques Loeb matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Jacques Loeb?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Jacques Loeb.

Tags

  • 1859 births
  • 1924 deaths
  • 19th-century German Jews
  • American atheists
  • American physiologists
  • Emigrants from the German Empire to the United States
  • German physiologists
  • Jewish biologists
  • Members of the United States National Academy of Sciences
  • People from Mayen
  • Presidents of the American Society of Naturalists
  • Rockefeller University people

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