OBSERVATIONS AND DEDUCTIONS 23 



(3) The numbers of groups and the numbers of indi- 

 viduals in each group increase with every additional 

 pair of characters in which the parents differ, according 

 to the following scheme : 



For instance, if the parents differ in three pairs of 

 characters, there are eight groups in their hybrids' 

 progeny : 1 containing 1 individual, 3 containing each 

 3 individuals, 3 containing each 9 individuals, and 

 1 containing 27 individuals. 



(4) Since 2" gives the number of groups or kinds in 

 the hybrids' progeny, and 2 of these are the same as 

 the original parents, 2" — 2 gives the number of new 

 kinds, thus : 



n 



2« 



2»-2 



