. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. CYCLIC RESPIRATION IN CLEAVING EGGS 703 Figure 3 are shown curves (A, B) thus calculated for ACO2/At. They show a reproducible rhythm in CO2-liberation, with small bursts | of the cycle time before appearance of the division furrows, and corresponding dips are seen -]—•J of a cycle after this event, thus between the times of maximum and minimum rates of O2 uptake (Fig. 1). Percentage-wise, rate changes in CO, evolution are more ex- pressed than are the fluctuations in AO2: 11-18% versus 3-5% (Table I). Values for RO were cal


. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. CYCLIC RESPIRATION IN CLEAVING EGGS 703 Figure 3 are shown curves (A, B) thus calculated for ACO2/At. They show a reproducible rhythm in CO2-liberation, with small bursts | of the cycle time before appearance of the division furrows, and corresponding dips are seen -]—•J of a cycle after this event, thus between the times of maximum and minimum rates of O2 uptake (Fig. 1). Percentage-wise, rate changes in CO, evolution are more ex- pressed than are the fluctuations in AO2: 11-18% versus 3-5% (Table I). Values for RO were calculated (Fig. 4) from the curves of Figure 2. Respiratory quotients A 07 -£ 0-6h B 05 cr 04 2 0-3 0-1. B 07 06 05 0-A 0 FIGURE 4. hours Respiratory quotients calculated on basis of values for AC>2/At (Figs. 1 and 2) and ACO2/At (Fig. 3). Arrows indicate when cleavages 1-5 begin. were found to fluctuate by around the mean (dashed curve) and almost parallel to the values for CO.,. The mean values (dashed curve) for RQ were (A) and (B). DISCUSSION Below we discuss measurements of rates of oxygen uptake (AO2/At), of rates of gaseous exchanges when CO2 is not chemically absorbed in the system (A(O2 - CO2)/At), and of rates of carbon dioxide output (ACO2/At), obtained as the difference between results from the two first types of measurements. Finally, we shall discuss relations between uptake of O2 and output of COL. in the cleaving frog egg. We first discuss Figure 1, in which AO,/At was measured. In this experiment diffusion distances were somewhat long in comparison to other experiments (Zeuthen, 1946). The egg center was separated from the gas phase by mm, and the length of water column between the animal pole of the egg and the diver's gas phase was mm. In the following we make use of Linderstr^m- Lang's mathematical considerations as they were applied to previous experiments of the type here performed, and particularly to his Table III (Lind


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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology