58 Wisconsin Academy of Sciences, Arts, and Letters. 
generations, there are yet living members. Attention will he 
given to the effect of the first of these conditions later in the 
paper, and concerning the generations with record yet incom¬ 
plete it may he said that, as far as that record has yet been 
made in the case of any family, it generally has a striking re¬ 
semblance to the completed records of earlier generations of 
the same family. 
An objection to the reliability of the conclusion drawn from 
such records perhaps may be based upon an assumption that 
histories are printed of only such families as occupy the more 
prominent positions, and that therefore these records do not 
present a just picture of the complete facts in question. But 
a little consideration of the facility of intercourse beween the 
different strata of the American people and of the frequency 
of social ascents and descents will suggest the fallacy in such 
an objection. In fact, in all the families whose records have 
been examined, with possibly two exceptions, the close admix¬ 
ture of social strata is marked. It is not impossible that the 
historian of one of these two families exercised what he be¬ 
lieved to be a judicious selection in omitting the less reputable 
lines of descent from the common ancestor; and the record of 
the other family extended only through three generations' from 
the immigrant, who was a rather influential man of colonial 
times, as were many of his descendants in their own genera¬ 
tions. Those two families, designated in the accompanying 
table by the letters B and S, present the lowest mean ages of 
the eight families examined. But they are the two smallest 
families of the number, together comprising only three per cent, 
of the. entire number of lives considered, and can therefore 
cause but a very trilling modification of the result. They were 
included on account of the exceptional care which seemed to 
have been exercised in the preparation of the histories. 
The largest of the eight families is that of the two presidents, 
John and John Quincy Adams. But in this family, desig¬ 
nated by the letter A, there are branches which make it a typ¬ 
ical American family. The Loomis family is the second in 
size, and its record was selected on account of the extreme care 
exercised by its compiler, Prof. Elias Loomis, and also because 
