March 20, 1908] 



SCIENCE 



451 



was so great, however, and the number 

 of individuals so small, that these figures 

 may have no significance. More accurate 

 measurements, based on a far greater num- 

 ber of individuals, are to be made in the 

 near future. 



Such an adaptive response as an in- 

 crease in the density of the coat of hair, 

 following a transfer to a colder environ- 

 ment, is popularly believed to occur in 

 nature. On the other hand, an abridg- 

 ment in tail length, as a result of cold, has 

 been reported in the case of cats. Whether 

 or not such somatic changes are inherited, 

 or better, whether similar changes reap- 

 pear in the offspring, is a subject under 

 investigation by the author. 



Physical Identity in Duplicate Twins: H. 



H. "VViLDEE, Smith College. 



Introduction. — Review of the morphol- 

 ogy of the epidermic patterns in man, as 

 brought out by the work of previous years, 

 chiefly that of Inez Whipple [Wilder]. 

 In the foot of a typical pentadactylous 

 mammal there are eleven walking pads, 

 surrounded by folds of skin, arranged in 

 such a manner that the pads are embraced 

 by the prolongations of two, three or four 

 triradii. This formation, which is a high 

 relief in walking mammals, becomes re- 

 duced to an approximately plane si;rface 

 in primates, i. e., a picture of the former 

 relief. This loss of functional significance 

 has, however, resulted in a more or less 

 complete reduction of the individual fea- 

 tures, and thus the patterns assumed by the 

 epidermic ridges in man represent various 

 degrees of reduction of the fundamental 

 plan and are individually extremely vari- 

 able. They also normally show little tend- 

 ency to a bilateral symmetry, so that 

 the patterns on the two hands or the two 

 feet of a given individual are usually quite 

 different. 



Exhibition of the Prints of a Set of 



Ttvins.— [Set No. XX. of the author's col- 

 lection.] These are the prints of two 

 small boys in Portland, Me., Henry and 

 Bernard. They are first of all remarkable 

 in that the hands show the eleven typical 

 patterns complete, a case so rare that it 

 does not occur otherwise in a collection of 

 the palm prints of about 450 individuals, 

 including very varied human races. Aside 

 from a striking resemblance between the 

 four sets of members the prints show the 

 characteristics which are usually to be 

 noted in cases of true duplicates, viz : 



(») Bilaterality, so that all four palms 

 have virtually the same pattern. The same 

 is true of the soles. 



(&) A remarkable reversal of the apical 

 or fing-er-pattern of the index finger. The 

 right pattern of one is an ulnar loop, while 

 that of the other is radial ; on the left 

 hand the pattern of the first is radial 

 while that of the other is ulnar. This con- 

 dition, while not always found in twins 

 which seem to be duplicate, has been ob- 

 served in one side at least in more than 

 half of the cases. 



Conclusions.— 'I^XQ practical impossibility 

 of finding so close a correspondence in any 

 two children normally related, together 

 with the other conditions noted, lead to the 

 inevitable conclusion that in such twins we 

 have a condition from the germ on that is 

 unlike that which obtains in normal indivi- 

 duals. If we accept the most probable 

 theory to account for the origin of such 

 twins, viz., their origin from a single egg, 

 it then follows that the general form of the 

 epidermic patterns is predetermined in the 

 germ immediately after fertilization, in 

 short that in duplicate twins nature tries 

 for us the important experiment of making 

 two individuals out of the same germ-plasm 

 and that the study of their palm and sole 

 markings shows better than any other 

 known features how great is the resem- 



