NUMBER OF CHROMOSOMES 

 A B 



145 



FIG. 70. 



Normal and abnormal polar body formation in A scaris megalocephala uniralens. (Boveri, Ergebnisse, 1904.) 

 A, normal series ; B, abnormal series. In each, i is anaphase I. ; 2, metaphase II. ; 3, polar body formation 

 completed ; 4, fertilization, the ^ nucleus below in each figure. C, embryo derived from series B, showing 

 three chromosomes in the germ track, and only one polar body, with two chromosomes. 



