Jacobus Marinus Janse

Jacobus Janse

Jacobus Marinus Janse (born February 9, 1860 in Middelburg , † March 31, 1938 in Zeist ) was a Dutch biologist.

Life

Jacobus Marinus was the son of the mathematics teacher Leendert Janse (born December 31, 1818 in Brouwershaven; † February 27, 1898 in Amsterdam) and his wife Cornelia van Nederveen, who was married on June 30, 1847 (born June 30, 1822 in Middelburg; † February 1, 1904 in Utrecht). He attended the Higher Citizens School (HBS) in Amsterdam and enrolled at the University of Amsterdam in 1880 at the age of twenty . As a student in 1881 he answered a botanical question, which was rewarded with a gold medal. On December 4, 1885, he received his doctorate on the subject of Over de medewerking der mergstralen aan de waterbewegung in het hout ( German  about the involvement of the marrow rays in the movement of water in wood ) in Amsterdam as a doctor of botany and zoology.

In 1885 he became botanical assistant to Willem Frederik Reinier Suringar at the University of Leiden and in 1890 he became a manager of the botanical garden in Bogor . Various articles by him have appeared in the specialist journals of his time. For example in the German Yearbook for Scientific Botany , in the Annales du Jardin botanique de Buitenzorg and in the journals of the Royal Dutch Academy of Sciences. Above all, his three-part work in the Medeelingen van 's Lands Plantentuin , which appeared from 1891 to 1898, received wide attention. His investigations dealt with the diseases of tropical plants, the transport of water through the plants and the polarization phenomena in them.

On March 17, 1899 he was appointed professor of botany at the University of Leiden, which task he took on on November 1, 1899 with the introductory speech De voeding der hoogere planten ( German  The performance of higher plants ). In connection with this, he was also the head of the Hortus Botanicus Leiden . Under his direction, a botanical laboratory was set up on Nonnensteg from 1904 to 1906, for which he gave the inauguration speech on October 18, 1908. After he had been secretary of the academic senate in 1913/14, he led the fortunes of the Leiden university as rector of the alma mater in 1914/15 . In the latter capacity he gave the speech on February 8, 1915 Een physiologische vergelijking tusschen plant en dier ( German  A physiological comparison between plants and animals ).

Due to his age of 70, he retired on January 30, 1930 and left the university on September 15, 1930. He spent the last years of his life with his children in Zeist, where he was buried on April 4th after his death. Janse was a third class knight of the Russian Order of St. Anne .

family

Janse married on December 5, 1889 in Leiden with Katherina Hermina Sissingh (born February 9, 1860 in Harlingen, † March 27, 1941 in Zeist), the daughter of Albertus Sissingh (born April 11, 1832 in Godlinze; † November 20 1874 in Rotterdam) and his wife Bertha R. Engelsman, who married on December 23, 1856 in Delfzijl (born October 19, 1834 in Appingedam; † January 17, 1919 in Blaricum). Children have emerged from marriage, of which we know:

• Dr. Leendert Cornelis Janse (* July 10, 1891 in Bogor; † October 14, 1971 in Leeuwarden) he married on March 20, 1925 in The Hague with Anna Maria Susanna Hauwert (* September 12, 1894 in Amsterdam), the daughter of Pieter Hauwert and Catherine Mussert. On October 18, 1946, the marriage was divorced and he concluded another marriage in April 1947 with Maria Gerbrig Feddema (born October 13, 1909 in Leeuwarden; † March 2, 1993 ibid).
• Cornelia Albertina Janse (born July 13, 1893 in Bogor; † December 24, 1980 in Leiden)
• Catharina Jacoba Janse (born April 11, 1895 in Bogor; † October 15, 1962 in Leiden)

Works (selection)

• Failed the onderzoekingen, performed aan de Nederlandsche tafel in the zoological station of Dr. Dohrn te Napels. 1887
• De groei van de bloembladeren van Cypripedium caudatum Ldl. en van Uropedium Lindenii Ldl. 1887
• The permeability of the protoplasm. 1888
• Sereh schijnselen. 1891
• Het voorkomen van bacteria in suikerriet. In: Mededeelingen uit 'S lands plantentuin. Bogor, 1891 9 vol. 9, 56
• Overzicht van de results der wetenschappelijke onderzoekingen performed aan of met behulp van 's Lands Plantentuin te Buitenzorg. Batavia 1892
• The Root Endophytes of Some Javanese Plants. 1896
• De stikstof-voeding van koffie en other plans. 1896
• Les endophytes radicaux de quelques plantes javanaises. Leiden 1896
• Les endophytes radicaux de quelques plantes javanaises et quelques mots sur le développement d'une petite truffe. Leiden 1896
• De la Déhiscence du fruit du Muscadier. 1899
• De nootmuskaat-cultuur in de Minahassa en op de Banda-eilanden. In: Mededeelingen uit 's Lands Plantentuin. Bogor 1898
• De voeding der hoogere planned: Speech, uitgesproken bij de aanvaarding van het hoogleeraarsambt aan de Rijks-Universiteit te Leiden, November 1st, 1899. Leiden 1899
• Speech given at the opening of the Botanical Laboratory of the Rijks-Universiteit te Leiden on October 28th 1908. Leiden 1908
• A physiological vergelijking tusschen plans en dier: Rede, uitgesproken op the 340th verjaardag of the University of Leiden. Leiden 1915

literature

• Prof. Dr. JM Janse †. Oud-hoogleeraar in de plantkunde aan de Leidsche Universiteit. In: Leidsche Courant. April 1, 1938 page 3, Stads-Nieuws department
• Prof. Dr. JM Janse †. Oud-hoogleeraar in de plantkunde. In: Leidsch Dagblad. April 1, 1938, p. 1
• How is that? 1902. Biographical Naamlist, withered de Vraag "Wie is dat?" answered with mededeeling omtrent Levensloop, Werken enz. ten optichte van all Landgenooten, the door Ambt of Operating, beofening van Kunst of Wetenschap op den Voorgrond treden, in Dagblad of Tijdschrift, of van zich doen hooren. Vivat, Amsterdam, 1902