160 NATURAL INHERITANCE• [CHAP.

are Artistic. Therefore no, person whose Grade in the Art-Scheme does not exceed 70° can be reckoned as Artistic. Referring to Table 8 we see that the value of D for the Grade of 70° is + 0.78 ; consequently the art-measure of an Artistic person, when reckoned in units of the accepted scale, must exceed P+0-78.

The average art-measure of all persons whose Grade is higher than 70°, may be obtained with sufficient approximation by taking the average of all the values given in Table 8, for every Grade, or more simply for every odd Grade from 71° to 99° inclusive. It will be found to be 1.71. Therefore an artistic person has, on the average, an art-measure of P + 1.71. We will consider persons of this measure to be representatives of the whole of the artistic portion of the Population. It is not strictly correct to do so, but for approxiinative purposes this rough and ready method will suffice, instead of the tedious process of making a separate calculation for each Grade.

The M of the Co-Fraternity born of a group of Mid-Parents whose measure is P + 1.71 will be P + (3 x 1.71) or (P + 1.4). We will call this value C. The Q of this or any other Co-Fraternity may be expected to bear approximately the same ratio to the Q of the general population, that it did in the case of Stature, namely, that of 1.5 to 1.7. Therefore the Q of the Co-Fraternity who are born of Mid-Parents whose Art-measure is C, will be 0.88.

The artistic members of this Co-Fraternity will be those whose measures exceed {P + 0.78}. We may write this