. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 314 HOMER W. SMITH AND G. H. A. CLOWES. TABLE I. NINE EXPERIMENTS ON THE INFLUENCE OF H-IoN CONCENTRATION ON MATURATION OF Asterias EGGS. Per Cent. Permanently Immature. pH 7-2 7-4 9i 72 58 32 28 45 30 6 o 88 20 44 40 23 40 12 4 o 99 90 82 43 26 8 27 5 i o 58 34 22 16 8 18 IO 4 o 76 80 68 63 48 50 35 31 o 93 76 69 46 60 64 25 IO I 95 88 7i 61 39 36 26 14 5 8 93 86 68 69 57 33 16 17 5 i 76 20 28 33 39 21 17 4 5. Maturation is practically inhibited at pH , a point at which normally fertilize
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 314 HOMER W. SMITH AND G. H. A. CLOWES. TABLE I. NINE EXPERIMENTS ON THE INFLUENCE OF H-IoN CONCENTRATION ON MATURATION OF Asterias EGGS. Per Cent. Permanently Immature. pH 7-2 7-4 9i 72 58 32 28 45 30 6 o 88 20 44 40 23 40 12 4 o 99 90 82 43 26 8 27 5 i o 58 34 22 16 8 18 IO 4 o 76 80 68 63 48 50 35 31 o 93 76 69 46 60 64 25 IO I 95 88 7i 61 39 36 26 14 5 8 93 86 68 69 57 33 16 17 5 i 76 20 28 33 39 21 17 4 5. Maturation is practically inhibited at pH , a point at which normally fertilized Asterias eggs will grow quite normally, and approximately the point at which the unfertilized egg retains its viability for the longest time. It should be noted in Table I. that the incidence of maturated eggs does not always increase uni- formly with increasing alkalinity, but that in some experiments the proportion of immature eggs falls to a low value on the acid side of neutrality, rises noticeably at pH (or ) and then falls to zero at This irregularity in the influence of H-ion concen- tration on the maturation process is not affected by washing sev- eral times in the respective pH solutions. It appears, therefore, to be attributable to alterations in the egg cortex rather than to the activity of some substance in the supernatant fluid. THE INFLUENCE OF H-IoN CONCENTRATION ON Choetopteru* EGGS. The Chcetopterus egg differs from echinoderm eggs in that it is activated by sea water to which HC1 has been added, as Loeb showed many years ago. This activation, though not qualitatively nor quantitatively sufficient to produce normal larvae, makes it necessary to consider separately the consequences of exposing the unfertilized egg to acid solutions, and the effects of such ex- posures on subsequent fertilizability. Like the egg of Asterias, the Chcetopterus egg is ashed immature; though the germinal vesicle breaks down when the egg is placed in. Please note that t
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
