THE 



AMERICAN NATURALIST 



Vol. XLVII November, 1918 No. 563 



THK HFFECT ON THE OFFSPRING OF INTOXI- 

 CATING THE MALE PARENT AND THE 

 TRANSMISSION OF THE DEFECTS 

 TO SUBSEQUENT GENERATIONS 



Dr. CHARLES R. STOCKARD 

 Anatomical Laboratory, Cornell Medical College, 



It is a thoroughly demonstrated fact that the fertilized 

 egg may be so treated or modified during development as 

 to cause it to give rise to abnormal embryos of definite 

 types. Experiments on the unfertilized egg or female 

 germ cell are not nearly so numerous, are more difficult 

 to perform, and the results are not so decided. The treat- 

 ment of the male germ cell, or spermatozoon, so as to 

 modify it and to cause a modified development of the egg 

 which it subsequently fertilizes, is an experiment which 

 has rarely been performed with success. In the present 

 communication we wish to consider rather briefly the 

 various methods of treating or modifying the sperma- 

 tozoon or male germ cell and the result of this modifica- 

 tion on the embryo which arises when such a spermato- 

 zoon fertilizes an egg. In order to fully appreciate the 

 results obtained by experiments on the sperm it becomes 

 necessary to refer from time to time to the effects derived 

 when the egg is similarly treated. 



Since the positive literature bearing on the artificial 

 modification of the sperm is not extensive, I shall first 

 consider it in a general way, and devote the latter part of 

 the paper to the results obtained in a set of experiments 

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