. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. JOHN J. CHIAKULAS AND LAWRENCE E. SCHEVING minimum index, the difference indicated greater statistical significance (/> < ). It also can be seen from Table I and Figure 1 tbat the mitotic rate at 10 :30 is twice the average rate for all hours and 10 times the minimum rate recorded at 6:30 The minor rise in the rate of cellular division observed at 2:30 has no statistical significance. In the pond animals, two peaks of high cellular division occur—one at 12 :30 when the mean mitotic index reache
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. JOHN J. CHIAKULAS AND LAWRENCE E. SCHEVING minimum index, the difference indicated greater statistical significance (/> < ). It also can be seen from Table I and Figure 1 tbat the mitotic rate at 10 :30 is twice the average rate for all hours and 10 times the minimum rate recorded at 6:30 The minor rise in the rate of cellular division observed at 2:30 has no statistical significance. In the pond animals, two peaks of high cellular division occur—one at 12 :30 when the mean mitotic index reaches the value of ± , and another at 2:30 when the mean mitotic index of ± is recorded (Table I; Fig. 2). When these peak values are compared to the daily over-all mean mitotic Ul U 8 o o I' Id M O g x Ul o o t- o »- z u Z. 1 8 9 AM 10 11 12 1 2 3 4 5 6 PM 1 8 9 10 II 1 2 3 4 AM 5 I H OUR OF D A Y FIGURE 2. Mean indices, at two-hour intervals over a 24-hour period, for mitotic rate of gastric mucosal epithelium of pond animals. index of ± , they are not statistically significant. However, when these two values are compared to the minimum index of ± occurring at 6:30 , both the differences are statistically significant (p < ). When the mitotic indices of both laboratory and pond animals are plotted on the same scale (Fig. 3) a number of interesting observations are made. It is evident from the graphs (Fig. 3) that the rate of cell division follows a similar cyclic pattern in both groups, with a high period of activity between 10 :30 and 12:30 The 2:30 peak present in the pond group is not present in the laboratory group, although it is probable that the slight rise at 2:30 above the preceding period may represent a rather feeble acceleration corresponding to the peak present at this time in the pond group. Minimum mitotic activity. Please note that these images are extracted from scanned page images th
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
