56 



PHYSICAL BASIS OF HEEEDITY 



of the female are conspicuously larger than the others 

 (Fig. 25,(2). When reduction takes place the sizes of 



Maturation Divisions of Protlnor Q 



I 



■Sip 



Oocyte 



r Polar Spmdlc 2"^ Polar Spindle 



Mature C^^ and 

 Polav Bodies 



Fig. 26. — Reduced chromoBome group; and extrusion of polar bodies in Proienor. 



Maturation Divisions or Protenor (5 



^1 ' 1 1 



jf. 



OQ 







OO 



Ifim 



^o o 



^^ \id 



WQo 



Melaphase oj the ^ j/^ ^ O q 





1 ^' Spermatocyte -^/i^ 



Amapliase ot the 



P^ Spermalocyle %C^9o 



Metapkseoj the ^ -^J/^" 



2^ Spermatocyte 



Anaphase o| the 



Fig. 27. — Reduced chromosome group of male; and spermatogenesis in Protenor. 



the fused jDairs show that these two large chromosomes 

 must always unite with each other (Fig. 26). In the 

 male of certain species, as in Protenor (Fig. 27), the 



