1st. generation 



52 



Bald crossed with Bearded. 



I 

 I 



All Bald 



2nd. generation 



25% constant 



bald. 



I 



I 



50% inconstant 

 bald. 



25% constant 

 bearded. 



3rd. igeneration 



All bald 25% constant 50% inconstant 25% constant All bearded 

 bald. bald. bearded. 



4th. generation 



It will be seen from the above that the inconstant Bald forms segregate 

 in each generation into 75% Bald and 25% Bearded, or in the proportions 

 3:1. 



Mendel has given a simple and interesting explanation of his famous law, 

 a knowledge of which is essential to a proper understanding of the work at 

 Svalof , as indeed of that at most other breeding centres of the present day. 

 This explanation may be presented substantially as follows: 



In the higher plants and animals reproduction takes place as a result of 

 a union between two sexual cells (gametes), viz. a male and female cell. 

 Each gamete which is concerned in the origin of a given variety or species 

 possesses a definite factor for each of the characters by which such variety 

 or species is distinguished. Thus in the case of a red flowered variety of 

 plant, the gametes which are responsible for its being, possessed a factor for 

 red color. Similarly, a constant tall sort has a gamete with the factor for 

 tallness. A low growing form has a gamete with the factor for low growth, 

 etc. Now when a crossing is effected between say a black-kernelled and a 

 white-kernelled sort, a " black " gamete unites with a " white " gamete with 

 the result that a hybrid is produced which is black or dark brownish. This 

 is due to the fact that "black" is dominant over "white." When this dark 

 hybrid individual itself develops gametes, these do not possess the factor 

 for black or brown only, but rather a certain proportion of them possess the 

 factor for black and a certain proportion the factor for white. 



