. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. U2 MEL VIM SI'IH(,KL work at the University of Rochester, living colonies were shipped from Woods Hole b\ Air Express and kept in sea water, replaced at two-day intervals, at a tempera- ture of 1-2° C. Experimental results were similar under the two maintenance methods. (}itantitati\'c stmlies j reaggregation. For the experiments, it seemed desira- ble to have a quantitative expression of the extent of reaggregation at successive times. The following method was used. For each series of observations a fragment of fresh sponge
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. U2 MEL VIM SI'IH(,KL work at the University of Rochester, living colonies were shipped from Woods Hole b\ Air Express and kept in sea water, replaced at two-day intervals, at a tempera- ture of 1-2° C. Experimental results were similar under the two maintenance methods. (}itantitati\'c stmlies j reaggregation. For the experiments, it seemed desira- ble to have a quantitative expression of the extent of reaggregation at successive times. The following method was used. For each series of observations a fragment of fresh sponge was carefully dried with filter paper and a one-gram portion squeezed through bolting cloth into 40 ml. of sea water. Ten ml. of the suspension were transferred to a Syracuse dish and examined under the microscope at 430 X magnification. At intervals the aggre- gates were counted in each of five microscope fields taken at random, and the values were averaged. For these counts "aggregate" was defined as any coalesced group of four or more cells, and it is in this sense that the word will be used hereafter. Four cells constitute the smallest grouping that can be readily recognized as an aggregate as distinct from cells in contact, in routine examinations. Typical results over a 24-hour period are shown in Figure 1. Such a figure will be called a reaggregation curve and each of its ordinates, an aggregate count. The curve is satisfactorily reproducible under standard conditions; as an ex- ample, seven unselected curves are shown in Figure 2. Up to four hours the ex- treme variation of counts at any one time is about two aggregates. Between four and eight hours counts are somewhat more variable. But they are quite uniform again at 24 hours, at least under normal conditions: 12 such counts, unselected, range from to The progress of reaggregation as illustrated by these curves NORMAL REAGGREGATION OF MICROCIONA. 12 16 20 TIME IN HOURS FIGURE 1. Reaggregation of M
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
