. The Biological bulletin. Biology; Zoology; Marine biology. 300 THEO M. KONIJN populations was longer when the density in the attracting populations was lower. About 5^ hours elapsed after the deposition of the responding populations before the streams entered the aggregates in the attracting populations, and nearly all myxamoebae accumulated into a central mound of cells. The distance over which attracting myxamoebae were able to attract cells in responding popula- tions was measured after the cells in the attracting populations had aggregated and before cells in the responding populations f
. The Biological bulletin. Biology; Zoology; Marine biology. 300 THEO M. KONIJN populations was longer when the density in the attracting populations was lower. About 5^ hours elapsed after the deposition of the responding populations before the streams entered the aggregates in the attracting populations, and nearly all myxamoebae accumulated into a central mound of cells. The distance over which attracting myxamoebae were able to attract cells in responding popula- tions was measured after the cells in the attracting populations had aggregated and before cells in the responding populations formed their own aggregates. The distance between the center of the aggregate in the attracting population and the nearest side of the responding population was measured through an ocular micrometer at a magnification of 80 X. The attraction was marked positive only when cells in the responding drops moved outside the boundaries of the 600 800 1000 1200 UOO Distance of Attraction in Microns Figure 2. Four curves showing the percentage of responding populations that exhibit a response to developing aggregations in attracting populations derived from cell suspensions of different densities, and the distances between these aggregations and the nearest margins of the responding populations. The concentrations of the cell suspensions, from which the attracting populations were derived, are given. Diameter of the populations is mm. Results represent the average of three experiments. Results W^ashed myxamoebae were placed on hydrophobic agar of low rigidity to act as attracting and responding populations, and the cells comprising these stayed inside the boundaries of the droplets (Fig. la). When myxamoebae in the attracting populations aggregated, cells of the neighboring populations moved outside the margins of their droplets (Fig. lb). The diameter of both popula- tions was to mm. The attracting populations contained 500 to 1000 cells and the responding populat
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectb, booksubjectzoology
