�ber den zeitlichen Verlauf der Mitoseaktivit�t in Gewebekulturen

Circadian Rhythms and the Circadian Organization of Living Systems

“…It is supported by some direct evidence from tissue and organ culture. Enderle [14], many years ago, demonstrated a circadian rhythm of growth in Daucus tissue culture; Bunning has claimed [15] the persistence of a circadian oscillation in excised segments of hamster intestine; and there is evidence from several workers [18] that cell-division manifests a circadian periodicity in mammalian tissue culture. Finally, along these lines one notes that some degree of autonomy in the oscillations of individual tissues and organs is virtually demanded by the fact that single cells-at least as protists-manifest fully selfsustaining circadian oscillations which are formally identical with those of multicellular systems [16,17].…”

The occurrence of an endogenous circadian rhythm in a plant tissue culture.

“…Unequivocal evidence of the occurrence of endogenous rhythms in plant tissue cultures is therefore lacking. The endogenous nature of rhythmicity in animal tissue cultures (6,8) has also yet to be firmly established. The rate of CO., metabolism of the tissuies was measured with an infrared gas analyser (Grubb, Parsons and Company, Newcastle-Upon-Tyne.…”

The 24-Hour Scale: A Time Dimension of Adaptive Functional Organization

“…As to procedure and conditions, biophysical, biochemical, and other variables have revealed circadian rhythms. Illustrative examples include simple body temperature readings, blood-cell counts, tissue culture (35), the combination of differential centrifugation with tracers, and histology on organ samples (30). The number of reliable observations on circadian periodicity over such a wide range ofphenomena seems small when compared to the stock of other more classical physiological knowledge.…”