MITOTIC RESPIRATORY RHYTHMS IN SINGLE EGGS OF PSAMMECHINUS MILIARIS AND OF CIONA INTESTINALIS

¹ Laboratory of Zoophysiology, University of Copenhagen, and Kristinebergs Zoologiska Station, Sweden

1. In single fertilized marine eggs (Psammechinus miliaris, Ciona intestinalis) the rate of respiration shows a temporary decrease (5-10%) and reaches a minimum every time the egg divides. The findings were reproduced in 6 experiments out of 10. The method is not yet well enough controlled to permit definite statements as to whether or not deviating experiments should be referred to insufficient technique or to the eggs themselves.

2. The respiratory rhythm demonstrated resembles the one previously observed in the frog egg, in the Urechis egg and in several echinoderm eggs.