Wilhelm Hofmeister

from Wikipedia, the free encyclopedia
Friedrich Hofmeister

Friedrich Wilhelm Benedikt Hofmeister (born May 18, 1824 in Leipzig , † January 12, 1877 in Lindenau ) was a German botanist and university professor. Hofmeister was the first to recognize the similarity of the generation change of mosses , ferns and seed plants . Its official botanical author's abbreviation is “ Hofmeist. "

Life

The son of the music publisher Friedrich Hofmeister (1782–1864) - the Friedrich-Hofmeister-Verlag in Leipzig still exists today - attended the municipal secondary school in his hometown. The father was an avid plant collector and had brought together an extensive herbarium. The passion carried over to the son.

At the age of 15, Hofmeister joined the music store of Cranz in Hamburg , an acquaintance of his father's, as a volunteer . From 1841 he worked in his father's company, and soon he and his half-brother Adolph took over the father's business. The father continued to work as a publisher of scientific works, such as his friend Heinrich Gottlieb Ludwig Reichenbach . In 1847 Hofmeister married the factory owner's daughter Agnes Lurgenstein, with whom he would have nine children. In the same year he joined the Freemasons' Union and was accepted into the Leipzig Lodge "Apollo" .

Hofmeister had already dealt with the natural sciences as an autodidact in Hamburg, but returned to Leipzig to concentrate on botany . Important suggestions were the " Principles of Scientific Botany " by Matthias Jacob Schleiden and the work of Hugo von Mohl . In 1847 he published his first scientific work, which was shortly afterwards translated into French. For his work on the embryology of flowering plants, published in 1849, he received an honorary doctorate from the Philosophical Faculty of the University of Rostock in 1851 . After the publication of his work on the generation change, his scientific reputation was finally consolidated. But he was only to be appointed professor twelve years later . In 1854 the botany professorship at the University of Heidelberg became vacant due to the death of Gottlieb Wilhelm Bischoff . However, the faculty could not agree on a successor for years. In 1863 the Grand Ducal Ministry of Baden asked the faculty for their opinion on Hofmeister. When the faculty did not answer, the Ministry appointed Hofmeister on June 5, 1863 as full professor of botany and director of the botanical garden. In 1859 he was elected a member of the Leopoldina . From 1852 he was a member of the Royal Saxon Society of Sciences in Leipzig and from 1870 of the Göttingen Academy of Sciences . In 1865 he was accepted as a corresponding member of the Académie des Sciences and in 1874 of the Prussian Academy of Sciences .

In his institute, Hofmeister worked on issues relating to the history of development, and later also on experimental physiological topics. They were also happy years privately with his large family and friends such as the historian Heinrich von Treitschke . This period ended with the death of his wife in 1870 and the death of his youngest daughter from tuberculosis. There were also disputes at the university.

In 1872 Hofmeister accepted the appointment as successor to Mohl at the University of Tübingen . In 1873 he was elected to the American Academy of Arts and Sciences . In February 1876 he married Johanna Schmidt, a doctor's daughter from Lindenau near Leipzig. He received scientific honors such as the large gold Boerhaave Medal from the Dutch Society of Sciences. He lived to see his eldest daughter's wedding before he suffered a stroke in May 1876. He had to resign from his professorship and retired to Lindenau, where he died on January 12, 1877.

Researches

Fertilization of the flowering plants

In his first work: “ About the process of sexual fertilization of phanerogams ” (1847), Hofmeister dealt with the question, which was controversial in the middle of the 19th century, of what exactly actually happens during the fertilization of those who are covered. It was known that the pollen grains to the scar must be brought and that the pollen grain is not as a whole to the ovary reached, but that the pollen tubes to the ovules grow. This had Giovanni Battista Amici recognized 1830th Matthias Jacob Schleiden put forward the thesis that the penetrating pollen tube is solely responsible for the development of the embryo. Franz Unger and Hermann Schacht also shared this opinion .

In this work and in " The Origin of the Embryo of the Phanerogams " from 1849 on representatives of the evening primrose family, Hofmeister was able to correctly show that it is the female egg cell that develops into an embryo . However, he wrongly assumed that the fertilizing agent was passed on to the egg cell through the cell walls from the pollen tube through osmosis. The entry of the sperm cells into the egg cell could not be observed with microscopic techniques at the time.

Generational change of land plants

The greatest scientific achievement of the Hofmeister was the elucidation of the generation change of the land plants: the mosses, ferns and naked plants. The male and female reproductive organs of mosses and ferns, the antheridia and archegonia had been discovered and described by 1848. The connections were not yet known.

Hofmeister recognized the break in the development of plants at the transition from gametophytes to sporophytes : He was therefore able to equate the leafy moss plant with the prothallium of the fern and the sporogon of the moss with the fern plant. In a book review in 1850 he first used the word generation change for this process, a term that was previously only used in zoology.

In a footnote of his work from 1849 Hofmeister also laid the extension of these homologies to the softwoods ( conifers near). He noted that for this one had to compare the conifers with the ferns, which form two spore sorters (are heterosporous).

physiology

After 1857 Hofmeister turned to physiology. He worked, for example, on the rise of sap in plants, on movement phenomena and changes in direction of plant parts, on the water tension in tissues and on the growth laws of the trunks and leaves by means of vertically dividing cells. He also worked on the leaf position and the history of the development of the flowers.

From 1865 Hofmeister published a manual of physiological botany with Heinrich Anton de Bary , Thilo Irmisch and Julius Sachs , for which he himself wrote in the first volume the theory of the plant cell and the general morphology of plants .

Works (selection)

  • Investigations of the process of fertilization of the oenothereen. In Botanische Zeitung 5th vol., 1847. Column 785-792 .
  • The formation of the embryo of the phanerogams. A series of microscopic examinations. Leipzig 1849. Digitized .
  • Comparative studies of the germination, development and fruiting of higher cryptogams (mosses, ferns, Equisetaceae, rhizocarpeen and Lycopodiaceae) and the seed formation of the conifers. Leipzig 1851. Digitized . (Reprint: Hist. Nat. Classica 105. Cramer, Vaduz 1979)
  • The doctrine of the plant cell. (Handbook of Physiological Botany, Volume 1, Section 1) Leipzig 1867. Digitized .
  • General morphology of the plants. (Handbook of Physiological Botany, Volume 1, Section 2) Leipzig 1868. Digitized .

Honor

Hofmeisterstraße is named after him in the Leipzig district of Zentrum-Ost .

literature

Web links

Wikisource: Wilhelm Hofmeister  - Sources and full texts

Individual evidence

  1. ↑ Holger Krahnke: The members of the Academy of Sciences in Göttingen 1751-2001 (= Treatises of the Academy of Sciences in Göttingen, Philological-Historical Class. Volume 3, Vol. 246 = Treatises of the Academy of Sciences in Göttingen, Mathematical-Physical Class. Episode 3, vol. 50). Vandenhoeck & Ruprecht, Göttingen 2001, ISBN 3-525-82516-1 , p. 117.
  2. ^ List of members since 1666: Letter H. Académie des sciences, accessed on November 27, 2019 (French).
  3. ^ The origin of the embryo of the phanerogams, p. 58 .
  4. ↑ Gina Klank, Gernot Griebsch: Lexicon of Leipzig street names. Edited by Leipzig City Archives , Verlag im Wissenschaftszentrum Leipzig, Leipzig 1995, ISBN 3-930433-09-5 , p. 105.
personal data
SURNAME Hofmeister, Wilhelm
ALTERNATIVE NAMES Hofmeister, Friedrich Wilhelm Benedikt
BRIEF DESCRIPTION German music dealer, botanist and university professor
DATE OF BIRTH May 18, 1824
PLACE OF BIRTH Leipzig
DATE OF DEATH January 12, 1877
Place of death Lindenau