JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
Large numbers of crosses were made between Peas differing in respect 
■of each of these pairs of characters. It was found that in each case the 
offspring of the cross exhibited the character of one of the parents in 
almost undiminished intensity, and intermediates which could not be at 
once referred to one or other of the parental forms were not found. 
In the case of each pair of characters there is thus one which in the 
first cross prevails to the exclusion of the other. This prevailing 
•character Mendel calls the dominant character, the other being the 
recessive character.* 
That the existence of such " dominant " and " recessive " characters 
is a frequent phenomenon in cross-breeding, is well known to all who 
have attended to these subjects. 
By self-fertilising the cross-breds Mendel next raised another gene- 
ration. In this generation were individuals which showed the dominant 
character, but also individuals which preserved the recessive character. 
This fact also is known in a good many instances. But Mendel dis- 
covered that in this generation the numerical proportion of dominants to 
recessives is approximately constant, being in fact as three to one. With 
very considerable regularity these numbers were approached in the case 
of each of his pairs of characters. 
There are thus in the first generation raised from the cross-breds 
75 per cent, dominants and 25 per cent, recessives. 
These plants were again self-fertilised, and the offspring of each plant 
separately sown. It next appeared that the offspring of the recessives 
remained pure recessive, and in subsequent generations never reverted to 
the dominant again. 
But when the seeds obtained by self-fertilising the dominants were 
sown it was found that some of the dominants gave rise to pure dominants, 
while others had a mixed offspring, composed partly of recessives, partly 
of dominants. Here also it was found that the average numerical pro- 
portions were constant, those with pure dominant offspring being to those 
with mixed offspring as one to two. Hence it is seen that the 75 per 
cent, dominants really are not all alike, but consist of twenty-five which 
are pure dominants and fifty which are really cross-breds, though, like the 
cross-breds raised by crossing the two varieties, they only exhibit the 
dominant character. 
To resume, then, it was found that by self-fertilising the original 
cross-breds the same proportion was always approached, namely — ■ 
25 dominants, 50 cross-breds, 25 recessives, or ID : 2DR : IR. 
Like the pure recessives, the pure dominants are thenceforth pure, 
-and only give rise to dominants in all succeeding generations. 
On the contrary the fifty cross-breds, as stated above, have mixed 
•offspring. But these, again, in their numerical proportions, follow the 
same law, namely, that there are three dominants to one recessive. The 
recessives are pure like those of the last generation, but the dominants 
-can, by further self-fertilisatioD and cultivation of the seeds produced, be 
* Note that by these useful terms the complications involved by use of the 
•expression " prepotent " are avoided. 
