Throughout the decade of 1880-1890, Walther Flemming, Eduard Strasburger, Edouard van Beneden, and others elucidate the essential facts of cell division and stressed the importance of the qualitative and quantitative equality of chromosome distribution to daughter cells.

Charles Darwin and his son Francis publish the results of their studies on plant responses to light, explaining that phototropism (bending toward the light) results from light reaching the top of a plant's shoot.

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Walther Flemming publishes accurate depictions of cell division (mitosis) in Zellsubstanz, Kern und Zelltheilung.

Eduard Strasburger coins the terms CYTOPLASM and NUCLEOPLASM.

W. Flemming discovers lampbrush chromosomes and coins the term MITOSIS.

Karl Alfred von Zittel describes an exceptionally well-preserved pterosaur wing showing flight membranes in detail.

Charles Darwin publishes his final letter to Nature, on the dispersal of freshwater bivalves. His obituary appears the same month. In this paper, Darwin acknowledges the assistance of W. D. Crick or Northampton. Later, Crick's grandson — Francis Crick — will be one of the co- discoverers of the structure of DNA.

August Weismann points out the distinction in animals between the somatic cell line and the germ cells, stressing that only changes in germ cells are transmitted to further generations.

Edouard van Beneden announced the principles of genetic continuity of chromosomes and reported the occurrence of chromosome reduction at germ cell formation. The sperm and egg are haploid and fertilization restores the diploid chromosome number.

Wilhelm Roux offers a possible explanation for the function of mitosis.

William Keith Brooks, a professor at The Johns Hopkins University, publishes The Law of Heredity: A Study of the Cause of Variation and the Origin of Living Organisms. Although this speculative work did not significantly advance the understanding of heredity, brooks' thinking is important because during his career he provided instruction to and supervised the early research of Thomas H. Morgan, Edmund Beecher Wilson, and William Bateson — ultimately some of the most important contributors to the new science of genetics.

Pierre Émile Duclaux introduces the custom of designating an enzyme by the by the name of the substrate on which its action was first reported and adding the suffix -ase.

During 1884-88, identification of the cell nucleus as the basis for inheritance was independently reported by Oscar Hertwig, Eduard Strasburger, Albrecht von Kölliker, and August Weismann.

Gregor Mendel dies on January 6th, without ever knowing that his work on peas would lead to the transformation of biological research.

Walther Flemming, Eduard Strasburger and Edouard van Beneden demonstrate that chromosome doubling occurs by a process of longitudinal splitting. Strasburger describes and names the PROPHASE, METAPHASE, and ANAPHASEstages of chromosomal division.

August Weismann formulates the germ-plasm theory which held that the germ plasm was separate from the somatoplasm and was continuous from generation to generation.

Carl Rabl theorized the individuality of chromosomes in all stages of the cell cycle.

Walther Flemming observed sister chromatids passing to opposite poles of the cell during mitosis.

Francis Galton devised a new useful statistical tool, the correlation table.

Hugo de Vries (Holland) discovers aberrant evening primrose plants at Hilversum, Holland. Experiments with these extending over 15 years formed the basis for his mutation theory of evolution.

A. Ficatier publishes an account of the discovery of a trilobite perforated with two holes (perhaps to hang on a thread) at a Magdalenian- age site in France. The fossil lends the site its name of La Grotte du Trilobite.

John Bell Hatcher develops the "ant hill method of collecting minute fossils," collecting hundreds of tiny fossil teeth and jaws pushed to the surface by ants. He even carries shovelfuls of ants and sediment to other fossil localities in need of excavation by the arthropods.

August Weismann elaborated an all-encompassing theory of chromosome behavior during cell division and fertilization and predicted the occurrence of a reduction division (meiosis) in all sexual organisms.

Edouard van Beneden demonstrated chromosome reduction in gamete maturation, thereby confirming August Weismann's predictions.

Wilhelm Roux put forth the suggestion that the linearly arranged qualities of the chromosomes were equally transmitted to both daughter cells at meiosis.

Harry Govier Seeley determines that dinosaurs consist of "lizard- hipped" (saurischian) and "bird-hipped" (ornithischian) branches.

German anatomist W. von Waldeyer names chromosomes.

Heinrich Wilhelm Gottfried von Waldeyer names the CHROMOSOME.

Theodor Boveri verifies August Weismann's predictions of chromosome reduction by direct observation in Ascaris.

Francis Galton publishes Natural Inheritance. In it he describes the quantitative measurement of metric traits in populations. He thus founds biometry and the statistical study of variation. Ultimately, he formulates the Law of Ancestral Inheritance, a statistical description of the relative contributions to heredity made by one's ancestors.