234 HARRIS HAWTHORNE WILDER. 



certain, while it is possible to interpret in a similar way the faint 

 indication of certain lines on the thenar area of the right. It is 

 also noteworthy that the type of pattern upon the right hand of 

 Fa, a quite unusual type, is practically identical with that which 

 her niece C has upon the same hand. This universality of the 

 thenar pattern in four individuals of the father's generation (8 

 hands) w T ould suggest dominance. 



Concerning the second possibility, that the character here 

 examined, the thenar pattern, is not in itself a Mendelian unit, 

 but is conditioned by two or more factors, this is rendered probable 

 by the many stages of modification, or degeneracy, represented 

 by the hands here represented, eight in the older generation, and 

 ten in the younger. It suggests the presence of a factor tending 

 to reduce the pattern to a series of parallel lines that follow the 

 strong line of flexion bounding the thenar region, the "Line of 

 Life" of the palmist; and the presence of the ancestral thenar 

 pattern, or some stage in its reduction, in so many hands of the 

 H family, may be due to the absence of this latter factor fully 

 as much as to the presence of a positive thenar pattern unit. 



Quite aside from all this, the fact that such grades in the re- 

 duction of a pattern may exist, and that for a given pattern 

 there may be found several series of them 1 is in itself a phenom- 

 enon of heredity at present inexplicable, for, while in such a 

 series we may find every step in a definite and continuous process, 

 the steps themselves do not occur in ontogenetic development, but each 

 step arises in an individual embryo precisely in the form which 

 that individual shall retain throughout life. Since, now, this 

 process of the degeneration of the ridge formation is from a 

 complex pattern to a series of parallel lines; and since the goal 

 sought in this process is in countless details, precisely what would 

 result from the action of external forces upon yielding ridges, as 

 such authors as Miss Whipple and W. Kidd have abundantly 

 shown, we have the startling phenomen of a Lamarckian en- 

 vironmental influence of a mechanical nature, which, while having 

 no visible effect upon the soma, so modifies the germ-cells that the 

 effect becomes transmitted to the descendants, and that probably 

 by Mendelian methods! There has thus developed a long series 



1 Cf. Miss Whipple, 1904, pp. 33Q-.352, esp. Fig. 48, p. 350. 



