1 62 CHAS. \V. METZ AXD JOSE F. NOXIDEZ. 



homologous chromosomes during synapsis, and, in the case of the 

 Diptera, must allow for such an approximation in every cell 

 generation (cf. Metz, '16) This would seem to necessitate the 

 assumption that the envelopes of homologous chromosomes could 

 unite. 



LITERATURE CITED. 

 Conklin, E. G. 



'02 Karyokinesis and Cytokinesis. Jour. Acad. Nat. Sci. Phila., 12. 

 Lee, A. Bolles. 



'20 The Structure of Certain Chromosomes and the Mechanism of their Divi- 

 sion. Quar. Jour. Micro. Sci., 65 : 1-32. 

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Recherches sur 1'eloment chromosomique dans la caryocinese somatique 



des Filicinecs. La Cellule 31 : 255-473. 

 McClung, C. E. 



'14 A Comparative Study of the Chromosomes in Orthopteran Spermatogenesis. 



Jour. Morph. 25 : 651-749. 

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'17 The Multiple Chromosomes of Hesperotettix and Menneria (Orthoptera). 



Jour. Morph. 29 : 519-605. 

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 No. 2. 

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i. 

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373-374- 

 Richards, A. 



'17 The History of the Chromosomal Vesicles in Fiindulus and the Theory of 

 Genetic Continuity of Chromosomes. BIOL. BULL., Vol. 32, No. 4, 

 April, 1917. 

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'16 The Spermatogenesis of Phyrnotettix ma gnus with Special Reference to 

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