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CONTE.VTS. 



III. The Foregoing Considerations applied to the Male 



Germ-cells ........ 



The male germ-cells also require division in order to reduce 



the ancestral germ-plasms ..... 

 The germ-plasms of the parents must be Contained in the 



germ-plasm of the offspring ..... 

 Advantages which the egg gains by the late occurrence of 



the ' reducing division ' . 

 The causes of unequal division in the formation of polar 



bodies ......... 



These causes do not apply to the sperm-cell 

 Different kinds of nuclear division occur in spermatogenesis 

 Some of these may be interpreted as 'reducing divisions' 

 The paranucleus ('Nebenkern ') of spermatogenesis probably 



contains the histogenetic nucleoplasm . 



IV. The Foregoing Considerations applied to Plants 



V. Conclusions as regards Heredity .... 



The germ-cells of an individual contain different combina 



tions of hereditary tendencies .... 



Dissimilarity between the offspring of the same parents 

 Identity of twins produced from a single egg 



VI. Recapitulation 



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