572 The American Naturalist. [July, 
lishment of a race characteristic. Between the maximum and 
minimum degree of flattening among the tibiæ found at Tick 
Island was a difference of 31%. 
Prof. Edward S. Morse (Shell Mounds of Omori) gives the 
percentage of nine recent Japanese tibiæ as 0.74, one tibia 
from the shell heaps of Omori 0.62, one from a shell heap in 
the province of Higo 0.5002. 7 
In Michigan platyenemism has been noticed to a marked 
degree. Mr. Henry Gillman (Smithsonian Report for 1873 
page 368) cites nine tibia from a number found by him in the 
great mound on the Rouge River and in the circular mound 
on the Detroit River. Of these the average was 0.486, the 
lowest being 0.402. i ; 
It is to be regretted that the average of the entire number 
found is not given. 
Of the very many tibiæ exhumed at Tick Island fifty-five 
were in condition for measurement, many being broken at a 
point too low for determination, while others were crushed. 
It is of course apparent that all tibie must be discarded 
where a lateral flattening exists through causes acting on 
the bone after interment, since measurements made without 
due care in this respect would give and unfairly, a very low 
percentage to the lateral diameter. 
All measurements are made with calipers in hundredths of 
an inch. Of the fifty-five tibiæ the least platycnemic meas- 
ured transversely .96 inch and antero-posteriorly 1.16 inch, a 
percentage of 82, while the two lowest (now in my possession) 
were respectively .72x1.41 and .75x1.45 or 51% and 51.7%, the 
average for the fifty-five tibie being 63.9%. ; 
In this connection it is possible that statistics as to tibiæ 
found by me in other mounds of the St. John’s may be useful 
for purposes of comparison. 
Per cent. 
Burial mound at Ginn’s Grove near Lake Jessup ; three 
tibiæ, intrusive burials, average T F 
Thirty-three tibiæ, original burials from base of 
mound average SE ana‘ an 
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