| + + - | 1 2 - | 1 - 1 | 1 2 2 | | M | - 1 - | 5 10 3 | 3 8 9 | | + | 2 2 2 | 11 10 3 | 9 24 19 | +----------------------------------------------------------------+ The frequency with which 1, 2, 3, 4, etc., sets were found to fall under the same index-heading, is shown in Table XVIII. TABLE XVIII. +----------------------------------------------------+ | No. of sets | | | | under same | Frequency of its | No. of entries. | | index-heading.| occurrence. | | |---------------|------------------|-----------------| | 0 | 83 | 0 | | 1 | 47 | 47 | | 2 | 47 | 94 | | 3 | 25 | 75 | | 4 | 16 | 64 | | 5 | 7 | 35 | | 6 | 3 | 18 | | 7 | 4 | 28 | | 8 | 1 | 8 | | 9 | 2 | 18 | | 10 | 2 | 20 | | 11 | 2 | 22 | | 14 | 2 | 28 | | 19 | 1 | 19 | | 24 | 1 | 24 | |----------------------------------------------------| | Total entries 500 | +----------------------------------------------------+ No example was found of 83, say of one-third, of the 243 possible combinations. In one case no less than 24 sets fell under the same head; in another case 19 did so, and there were two cases in which 14, 11, and 10 severally did the same. Thus, out of 500 sets (see the five bottom lines in the last column of the above table) no less than 113 sets fell into four classes, each of which included from 10 to 24 entries. The 24 sets whose Index-number is + M, + + + admit of being easily subdivided and rapidly sorted by an expert, into smaller groups, paying regard to considerable differences only, in the head-length and head-breadth. After doing this, two comparatively large groups remain, with five cases in each, which require further analysis. They are as follow, the height and eye-colour being added in each case, and brackets being so placed as to indicate measures that do not differ to a sufficient amount to be surely distinguished. No two sets are alike throughout, some difference of considerable magnitude always occurring to distinguish them. Nos. 2 and 3 come closest together, and are distinguished by eye-colour alone. TABLE XIX. Five cases of Head-length 8.0, and Head-breadth 6.1. Span. Body. Finger. Height. Eye-colour.