Carl Nägeli

Carl Wilhelm von Naegeli ( born March 27, 1817 in Kilchberg, † May 10, 1891 in Munich) was a Swiss botanist. Its official botanical author abbreviation is " Naegeli ".

Life

Naegeli was born the son of a doctor. He studied in Zurich from 1836 onwards medicine, but soon changed to botany and studied with Lorenz Oken and Oswald Heer. From 1839 he studied at the University of Geneva in Alphonse Louis Pierre de Candolle Pyrame. He was phil 1840 in Zurich with a thesis on The Cirsien of Switzerland to the Dr.. doctorate. After he studied in Berlin in 1841, he worked from 1842 to Matthias Schleiden at Jena University.

1849 Naegeli was appointed associate professor at the University of Zurich and in 1852 obtained an appointment to the Chair of Botany at the University of Freiburg im Breisgau. There he worked until 1856 and was then Professor of Botany at the Federal Polytechnic ( the predecessor of the ETH Zurich ) and at the same time at the University of Zurich.

The longest period of his academic activity Naegeli spent at the Ludwig- Maximilians- University of Munich, where he worked as Professor of General Botany and Microscopy from 1857 until his retirement in 1889.

Carl Wilhelm von Naegeli was one of the important botanists of the 19th century. At the time of his ministry, the biology changed decisively. Matthias Schleiden and Theodor Schwann proved that build all organisms from cells and develop. Charles Darwin formulated his theory of evolution. With the aid of microscopic, biochemical and biophysical methods provide new insights have been gained into the structures and functions of cells and tissues. This made it possible to recycle many processes in nature due to natural causes. The formerly widespread in natural philosophy and speculative theories, including teachers of Nageli Lorenz Oken, lost its influence on the biological thinking.

The importance of Carl Wilhelm von Naegeli for the further development of the entire Botany evidenced by the numerous students who are on various fields famous researchers were later: The algae researcher Karl Eduard Cramer (1831-1901), the founder of the anatomy of the Moose, Paul Lorentz ( 1835-1881), Hubert Leitgeb (1835-1888), who explored the evolution of liverworts, Simon Schwendenerstrasse, who became famous as the founder of " physiological anatomy ", Carl Prantl the Farnforscher, Julius Oscar Brefeld, of clarifying the course of development of many fungi and Carl Correns, one of the founders of the science of heredity. Anton Rehmann also studied for his Habilitation at Nageli plant anatomy.

In honor of Nageli a street was named after him near the Cologne Flora on February 8, 1955 in Cologne.

Research

Carl Wilhelm von Naegeli wrote at the age of 25 years, a work on the formation of pollen and described the division with great accuracy. The described by him " transitory Zytoblasten " were later identified as chromosomes. Next he examined the process of osmosis in unicellular algae. Along with Hugo von Mohl he distinguished himself as the first botanist to plant cell wall from inside the plant cell, and declared their growth by intussusception ( storage).

He first described the structure and function of spermatozoids in the cryptogams and examined the importance of lower fungi for the emergence of infectious diseases. For lasting scientific inventory of botany with Albert Peter jointly authored monograph The Hieracia Central Europe ( 1885-1889 ) was.

A key priority for Nageli dealt with the microscopy, which he along with Simon Schwendenerstrasse 1865 The microscope. The same theory and application wrote. In addition, he provides in his Handbook of microscopy among others, the first comprehensive account of the polarization optics along with its application to plant objects dar.

Nageli genetic and cytological research led him to the conclusion that "the totality of its properties inherited in reproduction of the organism as idioplasm ". He introduced the concept of a idioplasm in botany. This should be the one idioplasm plasma portion of the protoplast, which contains the "real assets", we would say today, the genotype. Naegeli writes: " In each nucleus the characteristics of all ancestors are included as attachments ".

With its Micellartheorie 1858 he presented a hypothesis about the sub-microscopic architecture of optically anisotropic appearing Biostructures ago and coined the term meristem. He postulated here that all plasma substances " from the various modifications of albuminoids " existed. Their molecules should then " combined to form crystalline molecular groups mingled in soluble and insoluble form, form a mostly semi-liquid slime-like mass." Next: "In the moistened state, each surrounded by a shell of water; when dry they touch each other. " The molecular groups, of which he assumed that they contained 72 carbon atoms, he called " micelles ". This hypothesis has proven to be true in many respects, for example with respect to the crystallinity of the cellulose fibrils and amorphous and high swellability of the " Intermicellarsubstanz " that corresponds to the presently known cell wall matrix.

In the Movement Mechanical - physiological theory of the theory of evolution (1884 ) Naegeli put his evolutionary views down. Because after the publication of Darwin's " Origin of Species " (1859 ) he made ​​an extensive study of the theory of evolution apart, agreed with her too, but found Darwin's interpretation (like this yourself!) The reshaping effect of the environment on the organism unsatisfactory and postulated a intermediate agent that " idioplasm " (see above), so that selection could act on designed by " internal causes " individuals - a logical anticipation of subsequent genetic material! However Nageli did not recognize the importance of the work of Gregor Mendel in this respect: He had sent him in 1866 one of the 40 reprints of his experiments on plant hybrids whose results Nageli theories disagreed ( as N. not yet figured with distinct genes). In an accompanying letter Mendel mentioned his Bastardierungsversuche hawk with herbs ( Hieracium ), who knew Nageli particularly well. Apparently estimated Nageli the value of Mendel's studies low because they came from a " practitioner ", " practitioner " relied his view on the experience without their accuracy check - what 's only " by the scientific experiment, called the attempt by the practitioner has nothing in common " ( Naegeli, 1877), was possible.

Naegeli, together with other researchers of his time a supporter of pleomorphism concept, which lost in the aftermath important. He thought about - to have observed that bacteria could be other types of decay and re- convening of the parts - in contrast to Robert Koch.

Naegeli on the concept of the oligodynamic returns describing a damaging effect of the metal cations ( positively electrically charged metal ions ), in particular of heavy metals on living cells.

Works (selection)

• On the Development of the pollen in the phanerogams. Zurich, 1842
• The individuality in nature with excellent consideration of the plant kingdom. Zurich, 1856
• Contributions to scientific botany., 1858
• Origin and concept of Natural History Art Munich, 1865
• The microscope: theory and application thereof (together with Simon Schwendenerstrasse ). Leipzig, 1867
• Theory of fermentation: a contribution to molecular physiology. Munich, 1879
• Mechanical- physiological theory of the theory of evolution. Munich / Leipzig, 1884

Swell

• Karl Mägdefrau: History of botany. Life and performance of renowned researchers. 2nd edition. G. Fischer, Stuttgart 1992. ISBN 3-437-20489-0.
• Ilse Jahn (ed.): History of biology. 3, neubearb. and ext. Edition. Nikol, Hamburg 2004, ISBN. 3-937872-01-9.