42O 



MARIE A. HINRICHS. 



rates. Colorimeter measurements were made of the rate of fad- 

 ing of echinochrome. The results of such experiments are rec- 

 orded in Table III. 



TABLE III. 



THE FADING OF ECHINOCHROME PIGMENT BY ULTRAVIOLET RADIATION. 



* Results are given as per cent, of color remaining after each exposure 

 Non-radiated egg-water is used as the control. 



Non-radiated egg-water was placed in one tube of the instru- 

 ment and used as a color standard. Radiated samples were placed 

 in the comparator tube. Three readings were taken for each 

 sample, and the ratios of color intensities calculated. In each case, 

 an average of the three results was compared with that of the non- 

 radiated control. The final ratios appear in Table III. It will be 

 seen that the ratios of color intensity in radiated lots as compared 

 with color intensities in non-radiated lots decrease more rapidly as 

 the length of the period of radiation increases. 



Normal egg-water, when added to a normal sperm suspension, 

 produces activation and agglutination of sperm, i.e., the sperma- 

 tozoa form regular spherical masses which persist for a short 

 period of time, and then break up. The persistence of the masses 

 is a function of the condition of the sperm, and of the concentra- 

 tion of active fertilizin in the egg- water. Radiation of egg- water 

 causes a reduction and finally a loss of agglutinating power. 

 Fewer dilutions of a given sample of egg-water are possible before 

 the last effective dilution is reached. The results of radiating egg- 

 water and the consequent loss of agglutinating power will be 

 found in Table IV. 



The rate of loss of agglutinating power does not exactly parallel 

 that of the loss of color. It appears that ultraviolet radiation is 

 more effective in accelerating the loss of agglutinating power than 

 the loss of color. A 2 min. radiation at 12.5 cm. reduces the ag- 

 glutinating power of a sample of egg-water by 50 per cent., but 



