Protozoa as precursors of metazoa: German cell theory and its critics at the turn of the century

Abstract

In 1902, when the new German journal for protozoology, the Archiv fiir Protistenkunde, published its first issue, Richard Hertwig was chosen to write the lead article, which he entitled "Protozoa and the Cell Theory." 1 Both the author and the subject were appropriate and significant choices, for Hertwig, as professor of zoology and comparative anatomy and director of the Munich Zoological Institute, was the founder of one of the leading centers for protozoological research in Germany. His credentials in the field of cell theory were no less impressive. In the 1880s, he and his brother Oscar (both former students of Ernst Haeckel at Jena) had carried out cytological studies of invertebrates that figured prominently in the development of embryology and cell theory. 2 Infused with a love of protozoa through his association with Max Schultze at Bonn, Hertwig had subsequently turned his attention to investigating the processes of fertilization and nuclear division in various groups of protozoa. He was therefore well qualified to discuss the current status of protozoa vis-a-vis cell theory and, on the basis of this evaluation, to suggest a future research program for protozoology.Hertwig's article proved to be an important one for the 1. Richard Hertwig, "Die Protozoen und die Zelltheorie," Arch. Protist., 1 (1902), 1--40.2. For the careers of the Hertwig brothers, see Richard Weissenberg, Oscar Hertwig (1849--1922): Leben und Werk eines deutschen Biologen (Leipzig: J. A. Barth, 1959). The articles by several of Richard Hertwig's students (written on the event of his seventieth birthday) in Naturwissenschafien, 8 (1920), 767--782,

Regulation of the dystrophin-associated glycoprotein complex composition by the metabolic properties of muscle fibres

“…Those findings could be explained either by the constraints placed on a cell through the limited functional capacity of the nucleus (e.g. the karyoplasmatic hypothesis of Strassburger and Hertwig amongst other 28,29 ) or as a consequence of the development of muscle with rapid contraction characteristics underpinned by glycolytic metabolism following gene deletion 30 . In the former, the muscle fibre would undergo enlargement without a commensurate increase in the amount of collagen.…”

Amoebae as Exemplary Cells: The Protean Nature of an Elementary Organism

“…70 Dobell, 1911. See Corliss (1989, Jacobs (1989), and Richmond (1989) for discussion of the debates over the legitimacy of comparing unicellular protozoans to the cells of higher plants and animals. one or more nuclei and is not subdivided into separate units.…”

The protozoon and the cell: A brief twentieth-century overview

“…Recall his monumental systematic monograph published exactly 150 years ago.) This defense occurred at the very time when the individuality of a single protozoon was on the verge of being denied, as mentioned on a preceding page (and see Jacobs 1989 andRichmond 1989). But a major thesis of young Dobell's was to denounce the allegedly preposterous claim that protists are related in any way to "cells" or to "cell theories."…”

“…Not only is the study of protozoa (and therefore the history of the field) dependent on the parallel development of microscopy, as I have particularly emphasized (Corliss 1978(Corliss --79, 1979, but it is also inexorably associated with the investigation of cells --the science of cytology --in general (see Churchill 1989;Jacobs 1989;Richmond 1989). Because of the extremely important use of these organisms/cells as model systems, their study today is also strongly linked to genetics, biochemistry, molecular biology, evolution, and, to a lesser extent, ecology and developmental biology.…”