236 Trans. Acad. Sci. of St. Louis. 
Average in place of Median Value in the series about to be 
studied. 
The accuracy of the average can be estimated by the 
formula:? 
E=>2+ 
ee - 
where # = Probable Error of Average, 
d = Probable Deviation from Average, 
n = Number of Observations. 
The values for # are given in Tables No. 6, 7 and 8. 
It has already been said that the Physiological Difference 
between the Individual and the Type is expressed by the 
Probable Deviation from the Average. According to Geissler 
and Uhlitzsch,? the interval between Average minus d@ an 
Average plus d increases with the age. The values of d found 
by them in their measurements of height standing are as fol- 
lows (page 33): 
PROBABLE DEVIATION (Acted). 
Boys. trls. 
AGE, 
= 
. = 7 =— Pe ER OKT CREM AR CAS RC ET Ce eee 3.4488 8.5926 
58 ND GENS SLE Oia Ak eure es Maw gs Ob SNe Cae 55.5's OEOOEL 3.7362 
; DCL tt MANET CORE Ree Sew oe es Slee oe ca. Tob wet ers. 3.8546 3.8293 
x ata bt SS SHOE SR ne SSN emir Some perth wrerp ib ca re sar ee 4.0067 3.7785 
BE ee Coie ee Phere Co Rb Fe WL ae eee Dee RT TIE 4.2265 
3 Mts) Mun ie PERT Se cee Te TET ey hone ene | 4.4125 
SE ETS aoe neneebe eas oboe res SERS ewan lure ieee. 4.5984 - 4.8013 
Be aE Nu selerk cave Ves v matee RRO AN DaNae tae e cake eee 5.2155 
NOE 28 FO hea ee as Vecakeas Cheb eer ey ie ee as 5.1479 4.8520 
The authors say concerning this table (page 34) : — 
© Hieraus geht hervor, dass diese Intervalle mit dem Alter 
‘‘im Allgemeinen zunehmen und es diirfte dies auch ganz 
‘* natiirlich erscheinen, da wohl anzunehmen ist, dass die das 
‘* Wachsthum hemmenden bez. férdernden Ursachen bei den 
-‘‘meisten Individuen ziemlich dieselben bleiben, den Unter- 
} Formulas (1) and (2) are contained in L. Stieda’s paper: Ueber die An- 
wendung der Wahrscheinlichkeitsrechnung in der cnc kode Statis- 
tik. Archiv fiir Anthropologie, Bd. xiv, 1882, S. 167-1 
3 Arthur Geissler and Richard Uhlitzsch. Die Rieko Se ee der 
_ Schulkinder im Schulinspectionsbezirk Freiberg. Zeitschrift des kiniglichen 
_ Sdchsischen Statistichen ‘ 
Bureaus, xxxiv, Heft 1 and 2, 1888, S. 28-40 
