. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. CENTRAL BODIES IN CYTASTERS. 383 each of the four types of cytasters (Types A, B, D and Ei), at one half hour, one hour and two hours after activation, are in each case the total of all the detailed percentages of the various experiments for that type for that interval, shown on Chart II. A few of the individual experiments do not coincide with the average behavior, but such discrepancies are accounted for by the considerable differences in astral phenomena produced by the wide variations of activation. Despite wide modifica
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. CENTRAL BODIES IN CYTASTERS. 383 each of the four types of cytasters (Types A, B, D and Ei), at one half hour, one hour and two hours after activation, are in each case the total of all the detailed percentages of the various experiments for that type for that interval, shown on Chart II. A few of the individual experiments do not coincide with the average behavior, but such discrepancies are accounted for by the considerable differences in astral phenomena produced by the wide variations of activation. Despite wide modifications of osmotic pressure, temperature, butyric-hypertonic treatment, and ether treatment, producing different percentages of cytaster types, different percentages of eggs containing cytasters, different percentages of cytolyzed eggs, and different sizes and numbers of cytasters, the relationship between clear central rays and the presence of central bodies holds good. DISCUSSION. The Origin of Central Bodies in Cytasters of Echinarachnius parma. The previously described experiments prove that when eggs have been similarly activated and therefore contain similar types and percentages of cytasters, if they are fixed with a variety of killing agents, central bodies are present only when the fixative coagulates the cytaster in such a manner that rays are distinctly fixed and extend to the center (Chart I.). When, on the other hand, a fixative capable of clearly fixing rays is kept constant, but the various environmental factors used in activation are modified, the same relationship holds good, and central bodies are present only when those environmental factors produce well-formed cytasters with clear central rays (Chart II.). Finally, when an optimum activation is used capable of producing well-formed cytasters, and they are fixed by a killing agent capable of fixing rays distinctly, if the cytasters are studied at close intervals after activation, it is found that they pass thro
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
