Chromosomes from oocytes of the newt Triturus cristatus carnifex have been photographed by means of the electron microscope. These chromosomes are shown to consist of single axial filaments, approximately 200 Å wide, with ‘lamp-brush’ loops attached at intervals along their lengths. Good fixation of the lamp-brush loops has not yet been obtained. These chromosomes are attached in pairs to their homologues at points which, in the past, have been considered to be chiasmata: it hasbeen assumed that the stage is diplotene of the first meiotic division. The singleness of the chromosome strands which we have observed is at variance with observations of diplotene in other material by means of the light microscope.

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