No. 563] EFFECT OF INTOXICATING MALE PARENT 645 



of part of the foreign sperm finally act as a poison and 

 cause the eggs to develop abnormally. The typo of mon- 

 sters in these crosses are similar to those produced by 

 treating the eggs with chemical poisons. In many cases 

 these sperm take no part in development hut initiate the 

 process by serving as a parthenogenetic agent. I left \\ in- 

 takes the same position, and further finds, that when the 

 foreign sperm is treated with radium the injurious sub- 

 stance contained in it is killed or destroyed so that the 

 spermatozoon initiates development by parthenogenesis 

 without later causing the development to be abnormal. 

 Bataillon's method of sticking eggs with fine platinum 

 needles to give artificial parthenogenesis is similar, Hert- 

 wig thinks, to the use of sperm intensively treated with 

 radium. The treated spermatozoon plays the role of the 

 platinum needle in Bataillon's experiment. The male 

 chromatin can no longer combine with the female chro- 

 matin, there is no amphimixis. Bataillon, by his sticking 

 method, obtained from 10,000 R. fused eggs only L20 

 hatched tadpoles, and but three metamorphosed, while in 

 some of Hertwig's radium experiments almost all hatched 

 from the jelly. 



The radium experiments of Hertwig give us the first 

 method of artificial parthenogenesis which offers promise 

 for use with mammals. Hertwig suggests that since arti- 

 ficial fertilization is possible in many mammals, one might 

 fertilize with semen which had been intensively treated 

 with radium so that the chromatin was destroyed, and 

 with such sperm artificial parthenogenesis in mammals 

 could be accomplished. Two years before Hertwig made 

 this suggestion Dr. Congdon was trying the effects of 



tomical laboratorv at Cornell and is now continuing these 

 experiments in the anatomical laboratory at Stanford 

 University ; up to now he has not succeeded in obtaining 

 fertilization with the modified spermatozoa, though of 

 course much experimentation is necessary in order to 

 establish the proper intensity of the treatment. 



