+----------------------------------- | BB´ | Bb´ | bB´ | bb´ -----+--------+--------+--------+-------- BB´ | BBB´B´ | BBB´b´ | BbB´B´ | BbB´b´ -----+--------+--------+--------+-------- Bb´ | BBB´b´ | Bb´Bb´ | BbB´b´ | Bbb´b´ -----+--------+--------+--------+-------- bB´ | BbB´B´ | BbB´b´ | bbB´B´ | bbB´b´ -----+--------+--------+--------+-------- bb´ | BbB´b´ | Bbb´b´ | bbB´b´ | bbb´b´ ----------------------------------------- It will be observed that there are more brown determiners in some combinations than others. For instance one of the sixteen contains four such determiners, viz., B, B´, B, B´, four contain three determiners, six contain two, four contain only one, and one contains none. Thus all but one of the sixteen contain at least one determiner and will therefore be brown in color but the depth of color will depend on the number of brown determiners in a given individual. This is more graphically represented in Fig. 19, p. 90. The largest number of similar individuals, six in all, contain two determiners each and represent an intermediate "blend" between the original brown-chaffed and white-chaffed strains. The deeper and the lighter browns due to more or fewer determinants in an individual would if one did not know the units in this case look like the fluctuations around this average which we might expect in a blend. [Illustration: FIG. 19 Diagram illustrating the proportionate distribution of determiners where either of two different determiners produces the same character, the degree of expression of the character depending on the number of the determiners present. The numerals indicate the number of brown determiners present in an individual.] Nilsson-Ehle found another significant case in wheat where one particular red-grained strain of Swedish wheat when crossed with white-grained strains produced red-grained offspring, but when these were interbred the F_{2} generation gave approximately sixty-three red to one white-grained individual. Here it was found that in the original red wheat there are three separate determiners which act independently of one another in heredity, any one of which would make red color; and that they together with their absences simply follow the Mendelian laws for a trihybrid.