Influence of Colchicine Alone and Combined with X-Rays on Paramecium

The Biological Effects of X-Rays on Mating Types and Conjugation of Paramecium Bursaria

“…x-rays and of vital stains upon paramecia but more recently Halberstaedter and Back (1943) observed the effect of the combined action of colchicine and x-rays and colchicine alone upon Paramecium caudatum. The concentrations of crystalline colchicine in the basic culture media were 0.0005 per cent, 0.00025 per cent and 0.000125 per cent with the x-ray intensity at the distance of the irradiated object being 80,000 r./m.…”

The Action of Colchicine on Cell Division in Human Cancer, Animal, and Plant Tissues

“…Halberstaedter and Back (1943) studied the effect of colchicine and X rays on Paramoecium caudatum because of the simplicity of the material and the ease with which the effects on the individual cells could be observed. Three concentrations of colchicine were used.…”

The Physiological Effects of Radiant Energy

“…In samples of the organism exposed a shorter time, giant and odd-shaped forms appeared after a few days. Study of the curves of survival suggested that two different processes were involved; one, an immediate lethal effe�t, perhaps affecting the cytoplasm with colchicine for forty-eight hours prior to irradiation to inter fere with mitosis, the sensitivity was reduced about one-half (24). Drosophila eggs make a convenient test object for radiation.…”