INTERPRETATION OF MENDEL'S RESULTS 



233 



plant were planted by themselves, Mendel was able to judge 

 the character of each plant by its progeny, and so demonstrate 

 to be in the blood characters that did not come to view in the 

 parents. 



Interpretation of Mendel's Results. — In seeking an explana- 

 tion of his numerical results Mendel came to the conclusion that 

 when those special cell- divisions are begun that are to result in 

 microspores giving rise to sperm cells, and megaspores pro- 

 ducing egg cells, the inheritance bearers received from the parents 

 of the hybrid become segregated, so that two of the four micro- 



FiG. 133. — Diagratn showing possible combination of two contrasting characters 

 during self -fertilization of a hybrid. A, row of sperm cells, B, row of egg cells, C, row of 

 fertilized egg cells. Further description in text. (After data by Gregor Mendel.) 



spores and megaspores from a grandmother cell obtain a partic- 

 ular character from one parent while two receive its mate from 

 the other parent (Fig. 126, I). 



Applying this theory to the hybrid pea with tendency toward 

 terminal flowers from one parent and toward lateral flowers 

 from the other, each flower of this hybrid would produce two 

 kinds of pollen or microspores and two kinds of embvyo sacs or 

 megaspores, resulting, of course, in two kinds of sperm and egg 

 cells. Now in pollination according to chance, which is the way 



