Page:Popular Science Monthly Volume 63.djvu/408

404 50 in a compartment. As practically worked out, the distribution of these prints in compartments would be an unequal one, and while certain of the compartments would have but a single representative, or be even empty, some of the others would have a much larger number than fifty, possibly even several hundred.

But the line formulæ are but a primary classification and do not by any means exhaust the resources of these very varying parts. As a secondary classification, for the farther subdivision of the palms, to be appended to the first and employed whenever expedient, the use of a pattern formula may be suggested. This is based upon the irregular occurrence of patterns such as occur normally in the simian hand and appear sporadically upon various localities of the human palm.

If we count as a pattern each place where there is a definite loop, whorl or noticeable disturbance of the usual even course of the ridges, although by doing so we violate certain of the underlying morphological principles as shown by the comparison with other mammals, we may expect to find any or all of five patterns, located as described in the previous article and corresponding roughly to the divisions into which the palm is divided by the lines of interpretation, viz., one thenar, one hypothenar and three interdigitals (palmar of the previous paper). Of these the thenar, of rare occurrence among people of the white race, is morphologically composed of the vestiges of two, a genuine thenar and the interdigital which corresponds to the interval between the thumb and index; the three interdigitals lie below the three intervals between the fingers from the index to the minimus; and the hypothenar appears upon the large eminence of the same name which forms the outer boundary of the palm.

A pattern formula will thus need five places, one for each of the five patterns in a prearranged order, and, again adopting the principle of placing in the first position a very obvious one, about which there is no doubt, the order suggested may be, hypothenar, thenar, first, second and third interdigital. When any one of these is present, it may be designated by an abbreviation, such as a capital H for hypothenar, Th (or better, the Greek θ) for the thenar, and 1, 3 and 3 respectively for the others. When absent, may fill the position, and when there is merely a rudiment, a small r may be added to the as an exponent. Thus a few representative pattern formula" would be the following, taken from actual cases: