Behavior of the Germ-cells 183 



sometimes sterile. This sterility is due apparently, in some cases 

 at least, to irregularities in the division of the germ-cells. When 

 we recall that at one stage in the development of the germ-cells 

 there may be a pairing and subsequent fusion of the ma- 

 ternal and paternal chromosomes, we can readily imagine that 

 any differences in their behavior at this time might lead to 

 disastrous results. 



LITERATURE, CHAPTER XI 



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