THE 



AMERICAN NATURALIST 



THE BEARING OF THE ORIGIN AND DIFFERENTI- 

 ATION OF THE SEX CELLS IN CYMATOGASTER 

 ON THE IDEA OF THE CONTINUITY OF 

 THE GERM PLASM. 1 



Carl H. Eigenmanx. 



At the meeting of the American Microscopical Society last 

 August I read a paper on the Evolution of Sex in Cymatogaster, 

 of which the present paper is a part. It is not, and was not 

 intended as a full discussion of heredity, but contains observa- 

 tions and conclusions forced upon me while tracing the sex 

 cells from one generation to the next in Cymatogaster aggregatus 

 Gibbons, one of the viviparous perches of California. 



Since writing it, I have received from Dr. Minot his article 

 " Ueber die Vererbung und Verjiingung," which is just being 

 republished in the Naturalist. I have though t best to present 

 my results as read at the Ithaca meeting, with a note written 

 after the receipt of Dr. Minot's article, although the details of 

 the observations on which the conclusions are based may not 

 appear for some time. 



