. The physical basis of heredity . of the thread continues as thetetrad becomes placed in the spindle in such a way thatthe first separation of the chromosomes takes place alongthe secondary split, , the first division is found in several other individuals of this speciesthat this same chromosome pair B^^ consist of unequalmembers as shown in Figures 48, 2 ar-h and 3 a-d. In48, 2 <? a distinct crossing of the threads is present. Theshape of the contracted chromosome (/ g h) and its posi-tion on the spindle show that one of the longer, and oneof the shorter strands pas
. The physical basis of heredity . of the thread continues as thetetrad becomes placed in the spindle in such a way thatthe first separation of the chromosomes takes place alongthe secondary split, , the first division is found in several other individuals of this speciesthat this same chromosome pair B^^ consist of unequalmembers as shown in Figures 48, 2 ar-h and 3 a-d. In48, 2 <? a distinct crossing of the threads is present. Theshape of the contracted chromosome (/ g h) and its posi-tion on the spindle show that one of the longer, and oneof the shorter strands passes to one pole, and similarly alonger and shorter to the other pole. The division here isin the plane of the secondary split, , equational. Theinequality in length of the conjugating pair makes thisconclusion certain in this case. CROSSING OVER AND CHROMOSOMES 109 In the second division of this chromosome the longerthread separates from the shorter one—the second istherefore rediictionaL It is evident, especially from this.
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectheredit, bookyear1919
