62 Wisconsin Academy of Sciences, Arts, and Letters. 
very considerable. Tbe small number recorded in family W 
as having died when nonogenarians is explained by the publi¬ 
cation of the family history in 1883. 
But despite these two conditions tending to make the statis¬ 
tics give support to the theory of deterioration in successive gen¬ 
erations, the investigation now presented makes no such re¬ 
sponse. We look in vain for evidence of a decreasing percent¬ 
age of octogenarians, or even those whose lives have extended 
into the succeeding decade. The slight tendency in that direc¬ 
tion shown in the 1800 line of the general table including all 
the families is no larger than may be easily explained by the 
reference to the surviving members of the latest generation. 
The percentage of deaths in each decade, as given for each 
generation of each family and of the families taken as a whole, 
has also been computed for the combined generations, and the 
results are shown in the lowest lines of the separate family ta¬ 
bles and also that of the families combined. The near ap¬ 
proach to identity between those lines of figures and the lines 
immediately above them to which attention has just been called, 
is very striking, the most mlarked deviation from, agreement be¬ 
ing in the three smallest families, B, S, and B. The close 
agreement in the two largest families, A and L, and in the closr 
ing table including all the families suggests the probable result 
of a more extended investigation, and gives no countenance to 
the theory that the American is not living to be as old as of 
yore on account of the wiser care which is taken lest he die 
early in life. 
