HEAT PRODUCTION BY THE EGGS OF ARBACIA 



PUNCTULATA DURING FERTILIZATION 



AND EARLY CLEAVAGE. 



CHARLES G. ROGERS AND KENNETH S. COLE.' 



The general problem of development has in it so much of the 

 unexplained that any attempt to add to our information by 

 attacks from new directions may seem warranted. The work 

 here reported was first undertaken several years ago, but was 

 not carried to a successful issue until this past summer because 

 of experimental difficulties unforeseen at the start. 



The work was originally undertaken in an attempt to check 

 the work of Warburg and of Loeb and Wastenys concerning the 

 oxygen consumption of eggs before and after fertilization. It 

 will be recalled that these investigators had found that immedi- 

 ately after fertilization there occurs a remarkable increase in the 

 rate of oxygen consumption, amounting to 4 to 6 times the 

 amount used before fertilization. It is to be assumed that there 

 is also a corresponding increase in the carbon dioxide production 

 of the eggs. This latter would, of course, be exceedingly difficult 

 to measure in the case of marine eggs. If there is any consider- 

 able increase in oxygen consumption following fertilization there 

 should be a corresponding increase in the amount of heat pro- 

 duced by the eggs as a result of the oxidation process. The 

 question to be faced was whether, with the facilities at our 

 command, we would be able to make a series of measurements 

 which would bear examination by a physicist. Preliminary tests 

 made in 1920 and 1921 indicated that the production of heat by 

 fertilized eggs was a measurable quantity. These tests, observed 

 in the latter year by a group of physicists who were visiting the 

 Marine Laboratory, proved to be sufficiently encouraging to 

 warrant further expenditures of time and money. 



1 Contribution from the Zoological Laboratory of Oberlin College, and from 

 the Marine Biological Laboratory, Woods Hole, Mass. To the Director and other 

 officials of the Marine Biological Laboratory we express our thanks for many 

 courtesies extended to us. 



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