MORPHOGENESIS IN MICRASTERIAS
H. WARIS
Department of Botany, University of Helsinki, Finland
and
P. KALLIO
Department of Botany, University of Turku, Finland
II. General Features of the Desmids
III. Normal Features of Micrasterias
IV. Culture of Micrasterias
V. Persistent Defects in Form
A. Uniradiate Cells
B. Aradiate Cells
VI. Enucleate Cells
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VII. Complex Cells
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VIII. Changes in the Chromosome Complement
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A. Polyploidy
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B. Aneuploidy
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IX. The Effect of Ultraviolet Radiation
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X. Effects of Chemical Compounds
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A. Effects of Weak Acids on the Nucleoli
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B. Effects on the Development of New Semicells
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XI. Theory of the Cytoplasmic Framework
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XII. Conclusions
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References
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I. Introduction
In the field of morphogenetic research the study of single cells is of
fundamental significance. Unicellular organisms or isolated cells of
plants and animals may serve as test objects. In the study of these,
various branches of biological science converge. It is obvious that the
success of such experiments will depend on the suitability of the test
objects for the study of the problems concerned. This is illustrated by
the excellent results obtained by Haemmerling and his school with
Acetabularia and by Sonneborn and his school with Paramecium. From
the present survey it will appear that the unicellular desmid genus
Micrasterias offers some particular advantages when the relative
importance of nucleus and cytoplasm in differentiation is to be studied.
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