ii6 Indianapolis Biochemical Meeting: Abstracts [Sept. 



by cytolyzing vvith distilled water equal quantities of fertilized and 

 unfertilized stained eggs and making up the liquids to equal vol- 

 umes. In each instance the liquid from the fertilized eggs showed 

 a strikingly darker color. 



These results indicate a sudden increase of permeability in 

 echinoderm eggs upon fertilization. 



The Stability of the Photogenic Material of the Lampyridae 

 and its Probable Chemical Nature 



F. ALEX. MCDERMOTT 



(Hygienic Laboratory, Public Health and Marine-Hospital Service, 



Washington, D. C) 



The photogenic Compound present in the Lampyridae is much 

 more stable towards atmospheric oxygen than has usually been 

 th^ught, especially when dried out of contact with air; it presents 

 many points of similarity to other known biologic products; from 

 embryologic and chemical considerations it appears probable that it 

 is a lipoid or a lecithin. 



The Gases of Swiss Cheese 



WM. MANSFIELD CLARK 



(Dairy Division Research Laboratories, Bureau of Animal In- 



dustry, Washington, D. C.) 



An apparatus is described for isolating the gas from the " eyes " 

 of Swiss cheese. Successful Isolation has been accomplished and 

 the gas analyzed. The constituent gases vary with the age of the 

 cheese. Further experiments are being conducted with the view 

 of determining, if possible, whether the nature of the gases and 

 their ratios can be used to determine the species of bacteria which 

 are thought to be responsible for the formation of the eyes. 



