MICHIGAN ACADEMY OF SCIENCE. 107 



and paternal chromosomes are equally represented in the daughter cells, but 

 it should not be inferred that strict segregation of the germ-nuclei is necessary 

 to bring about this result. It is not claimed that the individuality of the 

 germ-nuclei during embryonic development is a universal phenomenon ; there 

 are too many observations that give positive evidence to the contrary. Where 

 it exists, the separation of maternal and paternal chromatin-complexes into 

 distinct groups within a single nucleus affords a striking exemplification of 

 the deeper and more universal truth that each germ-nucleus is represented 

 in its entirety in every cell, somatic as well as germinal, of a developing 

 organism ; but the mingling of these two complexes probably makes no essen- 

 tial difference in the distribution of the chormosomes following mitosis. The 

 chief importance of the observations here recorded on the behavior of the 

 nuclei in the developing eggs of Cryptohrmichus lies in the fact that we have 

 here the material for an ocular demonstration of a principle long ago foreseen 

 by Huxley (1878) when he said: "The entire organism may be compared to 

 a web of which the warp is derived from the female and the woof from 

 the male." 



Zoological Laboratory, Michigan State Normal College, Ypsilanti. 



BEFERENCES. 



Conklin, E. G. 1901. The individuality of the germ-nuclei during the 

 cleavage of Crepidula. Biological Bulletin, Vol. II. 



Haecker, V. 1892. Die Eibildung bei Cyclops und Canthocamotus. Zool. 

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Haecker, V. 1895. Heber die Selbstandigkeit der vaterlichen und mutter- 

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Huxley, T. H. 1878. Article "Evolution," Encyclopaedia Brittanica, Vol. 

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Moenckhaus, W. J. 1894. The development of the hybrids between 

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May 30. 



