PALM AND SOLE STUDIES. 237 



a plastic material by the direct application of the most usual 

 objects, acting in the most usual way, and (3) since no modifica- 

 tion of an individual plan of configuration seems possible during 

 ontogeny, or as a result of continued action upon an individual, 

 we find ourselves confronted by the phenomenon of a complex series 

 of arrangements, each corresponding exactly at all points with the 

 direct result of the action of constantly applied external forces upon 

 plastic structures; and yet, although these external forces are con- 

 stantly applied, and are without the slightest visible result upon the 

 individual, positive results, cumulative in their effects, are actually 

 transmitted from parent to child. Furthermore, these results must 

 lie transmitted by the germ-cells, and are probably in accordance with 

 the Mendelian laws. 



One could hardly find a more startling combination of princi- 

 ples than the above, supporting at the same time the ideas of 

 Lamarck, Mendel, and Weismann, with Darwin left entirely 

 out, since with the reduction in the size of the friction-ridges and 

 the increase in the size of the body, they can be of no real selective 

 value above the Cercopithecidse; yet from a long and careful 

 study of a large amount of data (perhaps a thousand hand prints, 

 including the most varied human races, studied during fifteen 

 years) every one of the above conclusions seems amply substan- 

 tiated. The facts stand written upon the palmar and plantar 

 surfaces of mankind; the detailed record of their physical ex- 

 ertions and that of a long line of ancestors; these records are 

 inherited with numerous individual modifications, so that, except 

 in the case of duplicate twins, the offspring of the same two parents 

 are never quite alike; it is easily possible to arrange these in- 

 dividual modifications in developmental series, presumably cor- 

 responding to their evolution, and, when so arranged, they follow 

 closely the theoretical series of modifications which would be 

 induced by direct influence from the usual external mechanical 

 forces, in case these structures were sufficiently yielding to allow 

 it. 



Such are the conclusions which, from my study of friction-skin 

 configuration, I have reached at present. They seem inevitable, 

 and if so, are exceedingly important; and it is because they seem 



