PHYSIOLOGICAL KKKKCTS OF LACK OF OXYGEN .".'.'.; 



vi. THI: I:ITI:CT OK CVKHON DIOXIDK ri-ox THE PROCI:SSI;S OF 

 CLI:AYA<;I: i\ Tin: CTENOLABKI s I:GG 



1 1' eggs a iv int nxl urn I into a runvut of pure carl ion dioxide 

 (which has been carefully washed), we must expert, to obtain, 

 besides the etl'erts of mere lack of oxygen, the specific chemi- 

 cal effects of the CO 2 . Even though everything indicates 

 that the action of (..'O., is qualitatively different from the 

 action of simple lack of oxygen, such differences have only 

 rardy to my knowledge, been demonstrated directly in the 

 cell.' In the egg of Ctenolabrus, however, these differences 

 are very striking. If freshly fertilized eggs are introduced 

 into a stream of pure CO 2 , no trace of cleavage occurs, even 

 though the eggs are not kept on ice. Under similar external 

 conditions the eggs kept in hydrogen divided two or even 

 three times. The germs also die much more rapidly in 

 CO 2 than in hydrogen. This constitutes, however, only a 

 quantitative difference. A qualitative difference evidences 

 itself, however, immediately that the air is replaced by a 

 cm-rent of CO 3 in eggs in the two- or four-cell stage. In 

 these experiments the eggs were kept in a drop of sea-water 

 in an Engelinann gas-chamber. Anxvboid tot)en/e/ds ( ichicli 

 ir.Tf Jlrxf noticed at the />en'i>l/er</ of tlte drop) took place on 

 fin- surface <>f tin- e</i/x in some ten to fifteen minutes, when 

 acurrent of carbon il/o.rit/e tra* }>o:xxed //iro/<</// the cham- 

 ber. Whether the whole protoplasm or only the superficial 

 layer of the protoplasm takes part in these changes could 

 not be determined. I have made a series of camera draw- 

 ings of these movements, which I will reproduce here. 



Fig. IIS shows the outlines of the four cells of an egg at 

 the beginning of the experiment. Fourteen minutes later this 

 cell had the appearance shown in Fig. llt>. One of the four 

 cells, that which was directed toward the periphery of the drop 

 and first struck by the stream of carl ion dioxide, sent out anice- 



- LuKIl AND II AKHKSI V, I'jlU'.l' ' I .\rrllil\ Vol. LXI. 



