Beiträge zur Biologie der Pflanzen by Cohn, Ferdinand - 1870 - 1875: Untersuchungen über Bacterien

Ferdinand Cohn's landmark articles setting out sound principles for classifying bacteria

Title: Beiträge zur Biologie der Pflanzen, Volume 1 ( Breslau; J.U. Kern's Verlag; Erster Band; 1875 ). First Edition, 1st printing ( but 2nd printing of Zweites Heft ). Entire volume ( Erstes, Zweites and Drittes Heft ) containing two key articles by Cohn, Ferdinand ( 1828-1898 ) entitled :

1) Untersuchungen über Bacterien. pp. 127- 224 ( Zweites Heft ), including colour Plate III;

2) Untersuchungen über Bacterien.

Format : pp. [x], 131, [xii], 224, [iv], 224. 15 plates ( with several beautiful cromolithographs ). 8vo (152 x 224 mm). Contemporary light brown half-calf over marbled boards, with gilt title and fillets to spine. Lightly marbled text block.

Description: Considered to be a culturally and scientifically important milestone, Ferdinand Cohn's encyclopaedic knowledge of algae, fungi, protozoa and bacteria meant he was well placed to produce this 'tour de force' of bacterial classification, providing a rational basis for later work.

Item 1: Cohn first points out that earlier authors ( e.g. Ehrenberg and Dujardin ) were limited by the low power of contemporary microscopes; and Pasteur only gave microbes rather vague descriptions. Many of Cohn's scientific peers believed that multiple forms of bacteria derived from one organism subjected to varying conditions. Here, Cohn sets out certain principles on which he believed a classification should be based ( e.g. morphology ), as he was convinced that bacteria had unique characteristics which distinguished them as species. He divided them into four groups or tribes : Sphaerobacteria, Microbacteria, Desmobacteria ( to include the Genus Bacillus ) and Spirobacteria. Plate III illustrates a wide range of bacterial structures which are subjected to Cohn's new classification. " This paper illustrates some clear thinking regarding the problem of bacterial taxonomy ….. it is amazing that Cohn was able to analyze the problem as accurately as he did " ( Brock; Milestones in Microbiology ). " … one of the chief founders of the bacterial doctrines held to-day" ( Bulloch; The History of Bacteriology ). Reference: Garrison-Morton.com Item 2483.

Item 2: He continues to characterize various bacterial types; argues that some bacteria are closely related to blue-green algae. Plates V and VI further illustrate in colour a spectrum of bacterial forms, and he summarises the work with a two-page classification scheme.

There are six further articles by Cohn, including one on parasitic Algae and one on Volvox.

The volume also contains an article by Dr. J. Schroeter ( Zweites Heft, pp. 109-126 ) describing first use of the cut surface of a boiled potato to separate and grow mixtures of bacterial types – a novel technique relied on later by Robert Koch to generate pure bacterial cultures.

Condition : Minor wear to board edges; a few annotations in pencil in text, otherwise pages and Plates very clean. Plate V beginning to separate from its binding. Overall, a very good and completely un-restored exemplar.