ELECTRIC IMPEDANCE OF ASTERIAS EGGS.
The alternating current resistance and capacity of suspensions of unfertilized eggs of Asterias forbesi have been measured at frequencies from one thousand to sixteen million cycles per second. The plasma membrane of the egg has a static capacity of 1.10microf/cm.(2) which is practically independent of frequency. The suspensions show a capacity dependent on frequency at low frequencies which may be attributable to surface conductance. The specific resistance of the cytoplasm is between 136 and 225 ohm cm. (4 to 7 times sea water), indicating a relatively high concentration of non-electrolytes. At frequencies above one million cycles there is definite evidence of another element of which the nucleus is presumably a part.
Cole
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KS
Department of Physiology, College of Physicians and Surgeons, Columbia University, New York, and the Biological Laboratory, Cold Spring Harbor, Long Island.
Cole
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RH