. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 140 ERIK ZEUTHEN from the surroundings, gives the diver buoyancy and permits the pressure-sensitive air volume of the diver to be reduced almost ad libitum. Since the glass stopper is inserted without any grease, narrow passages are left which allow the air bubble in the diver to react with volume changes to outside pressure variations, created by the aid of an adjustable water manometer. The diver floats in the same medium which is in the neck of the diver; , in alkaline water, isotonic with the biological me- dium in t
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 140 ERIK ZEUTHEN from the surroundings, gives the diver buoyancy and permits the pressure-sensitive air volume of the diver to be reduced almost ad libitum. Since the glass stopper is inserted without any grease, narrow passages are left which allow the air bubble in the diver to react with volume changes to outside pressure variations, created by the aid of an adjustable water manometer. The diver floats in the same medium which is in the neck of the diver; , in alkaline water, isotonic with the biological me- dium in the bottom droplet. A long glass extension may be attached to the outer end of the stopper. This makes the diver float upside down ("inverted diver"), so that the organisms in the diver, if immobile, will come to rest on the meniscus be- tween air and water, not on the bottom of the diver, away from the air FIGURE 1. The diver. 0 Experiments with the diver are reported in the paper by Zeuthen (1950b). Figure 2 in that paper indicates that the diver is practically tight to gases. How- ever, in the first part of the experiment, an apparent respiration is often measured. This is explained by assuming that a diffusion equilibrium is gradually becoming established inside the diver. If, for instance, the diver is filled with fluids which are in equilibrium with air, but an oxygen bubble is introduced, gas goes in solution because oxygen is more soluble in water than is air: Equilibrium is established asymptotically. How long it takes before it is well enough established depends mainly on the gases involved, on the relative amounts of water and gas in the system, and on the diffusion distances in the water of the diver. In the diver used for the experiments on eggs of t/rtfr/n'.?, relatively much water was present in the system. Therefore the initial equilibration period was long (1-2 hours). It is important to remember that for disclosing a possible rhythm in respir
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
