224 
ANTHROPOLOGY: C WISSLER 
It may be said that, so far as the abundance of the elements goes, the 
system seems to play out at the end of the first eighth group in the 
periodic system. It may be of interest to note here, what has been 
pointed out in former papers, that it is just at this point in the system 
that the atomic weights cease any longer to be very close to whole nimi- 
bers, as they are for the Ughter weight elements. Also just at this 
point the exact formula given for the elements ceases to hold well. These 
facts do not mean however, that the system fails beyond the iron group 
of elements; for it is just among the heaviest elemeats that it received 
its verification by the actual decomposition of the elements into helium. 
The complete paper of which this is an abstract, will be published 
later. I wish to thank Prof. C. W. Balke of the University of Illinois 
for suggestions in regard to the relative abundance of the elements of 
the rare earth group. 
^ Harkins and Wilson, These Proceedings, 1, 276 (1915); /. Amer. Chem. Soc, 37, 1367- 
1421 (1915); Phil. Mag., 30, 723 (1915). 
2 Harkins and Hall, /. Amer. Chem. Soc., 38, 186-8, 203-5, 211-14 (1916). 
3 H. Buisson, Ch. Fabry, and H. Bourget, Astrophys. J., 40, 256 (1914). See also Demp- 
ster, Ann. Physik., 47, 792 (1915). 
"Wright, These Proceedings, 1, 590-5 (1915). 
^Farrington, Publications 120 and 151, Field Columbian Museum, Chicago. 
^ Clarke, The Data of Geochemistry, Bulletin 491, Department of the Interior (1911); see 
also Bulletin 616 (1915). 
'Lunn, in 'Tidal and Other Problems,' pp. 201-18, Carnegie Institution (1909). 
THE GENETIC RELATIONS OF CERTAIN FORMS IN AMERICAN 
ABORIGINAL ART 
By Clark Wissler 
AMERICAN MUSEUM OF NATURAL HISTORY. NEW YORK CITY 
Received by the Academy, March 2. 1915 
One of the most difficult problems in anthropology has been the 
working out of successive steps in the origins of particular traits of 
culture. The most intensive effort seems to have been made in studies 
on the evolution of decorative designs. By arranging designs foimd 
upon prehistoric or other pottery in order of their increasing con- 
ventionaHty, series have resulted, showing a clearly reaHstic drawing 
at one end and an almost entirely geometrical one at the other. Such 
series suggest that all these forms were arrived at by first drawing from 
real life and then by successive conventionaKzations arriving at a pure 
geometric form. The weak point in this interpretation is that there 
are no means of dating the units of the series, their arrangement being 
merely a matter of selection on the part of the observer. There are still 
