ULTRAVIOLET AND ARBACIA FERTILIZATION. 



429 



of the onset of agglutination to he a function of sperm activity. 

 The time during which the agglutinated masses remain intact also 



(See Fig. 3.) 



decreases with increased dosage. 



See-. 



FIG. 3. Delay in agglutinating reaction following radiation of sperm. 

 Ord : nates, number of seconds elapsed before the onset of agglutination with 

 normal egg-water. Abscissae, length of period of exposure, in seconds. 



The same conditions are found when egg-water is radiated for 

 a short interval, and then used to agglutinate normal sperm. Its 

 agglutinating capacity is reduced. Agglutination is delayed, and 

 the masses persist for a shorter period of time than when normal 

 egg- water is used with normal sperm. Longer exposures of 

 either egg-water or sperm, previous to mixture with normal sperm 

 or egg-water, respectively, produce larger irregular permanent 

 masses which " run into each other " forming a kind of reticular 

 mass throughout the suspension. 



TABLE X. 

 Loss OF AGGLUTINABILITY OF SPERM SUSPENSIONS FOLLOWING RADIATION. 



A. Sperm in concentration of 3 drops of i per cent, suspension per 10 cc. 

 sea-water. 



B. Sperm in various concentrations radiated for 30 sec. each. * abn- 

 aggregates were abnormal in appearance, and were permanent and " stringy." 



