The cell in development and inheritance . predecessors or contemporaries of Schleiden and Schwann should be especially mentionedRobert Brown, Dujardin, Johannes Miiller, Purkinje, Hugo von Mohl, Valentin, Unger,Nageli, and Henle. The significance of Schleidens, and especially of Schwanns, work liesin the thorough and comprehensive way in which the problem was studied, the philosophicbreadth with which the conclusions were developed, and the far-reaching influence whichthey exercised upon subsequent research. In this respect it is hardly too much to com-pare the Alikroskopische Untersuchuugeii
The cell in development and inheritance . predecessors or contemporaries of Schleiden and Schwann should be especially mentionedRobert Brown, Dujardin, Johannes Miiller, Purkinje, Hugo von Mohl, Valentin, Unger,Nageli, and Henle. The significance of Schleidens, and especially of Schwanns, work liesin the thorough and comprehensive way in which the problem was studied, the philosophicbreadth with which the conclusions were developed, and the far-reaching influence whichthey exercised upon subsequent research. In this respect it is hardly too much to com-pare the Alikroskopische Untersuchuugeii with the Origin of Species. INTRODUCTION 3 During the past thirty years the theory of organic descent hasbeen shown, by an overwhelming mass of evidence, to be the onlytenable conception of the origin of diverse living forms, however wemay conceive the causes of the process. While the study of generalzoology and botany has systematically set forth the results, and in ameasure the method, of organic evolution, the microscopical a. Fig. I. — A portion of the epidermis of a larval salamander {Amblystomd) as seen in slightlyoblique horizontal section, enlarged 550 diameters. Most of the cells are polygonal in form, con-tain large nuclei, and are connected by delicate protoplasmic bridges. Above at is a branched,dark pigment-cell that has crept up from the deeper layers and lies between the epidermal of the latter are undergoing division, the earliest stage {spireme) at a, a later stage (mitoticfigure in the anaphase) at b, showing the chromosomes, and a final stage {telophase), showingfission of the cell-body, to the right. anatomy has shown us the nature of the material on which it hasoperated, demonstrating that the obvious characters of plants andanimals are but varying expressions of a subtle interior organizationcommon to all. In its broader outlines the nature of this organiza-tion is now accurately determined; and the cell-theory, by whichit is formula
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectcells, bookyear1902
