Peeservation of the Life of the Egg 283 



That the first eight flasks had been thoroughly sterilized 

 was demonstrated by the fact that all the flasks remained per- 

 fectly clear and unclouded throughout the whole experiment; 

 and that three flasks which were not opened till the end of the 

 experiment, i.e., after ten weeks, were quite clear and each single 

 egg therein could be distinctly recognized. The flasks with 

 unsterilized sea-water became cloudy after only twenty-four 

 hours, and after two days the eggs had fallen a prey to bacteria 

 and no egg was any longer recognizable. The sterilized flasks 

 which were opened were always quite free from odor, while 

 the unsterilized flasks already smelled unendurably putrid after 

 one to two days. A microscopical examination of the sea-water 

 for bacteria always remained absolutely negative in the steril- 

 ized flasks, and was always quite positive in the other flasks. 

 In the flasks to which 2 c.c. of the putrid culture of starfish 

 eggs had been added, bacteria and infusoria were extremely 

 numerous from the first. 



Six hours after the beginning of the experiment, one flask 

 of each of the three series was opened, and the eggs examined 

 with a microscope. The appearance was the same in aU three 

 flasks : practically all the eggs were ripe, and a small number 

 were dark or black. What is of definite importance for us is 

 the fact that the percentage of dark, dead eggs was quite as 

 large in the sterile culture as in the unsterilized or befouled 

 sea-water. 



Twelve hours later, and therefore eighteen hours after the 

 experiment was started, another flask from each of the three 

 cultures was opened. This time practically all the eggs in the 

 sterile culture were dark or black, and a few already showed 

 decomposition into globules. The same percentage of eggs 

 in the two other cultures was also dark. Hence the eggs die 

 just as quickly in the sterilized flasks, which are absolutely bacteria- 

 free, as in the flasks which contain bacteria. Death takes place 

 from intrinsic causes and so quickly that the scanty bacteria 



