396 The Journal 
The first thing to strike the attention 
is that the first-born, who have some- 
times been supposed to be handicapped 
with all sorts of physical weakness from 
birth, are relatively more numerous 
than any other birth-rank. But the 
number of individuals in the last birth- 
ranks is somewhat surprising, in view of 
the generally accepted belief that the 
last child of a very large family tends, 
because of uterine exhaustion in the 
mother, to be defective, and is often an 
imbecile of the so-called Mongolian 
type. The table here given shows at 
least that the last-born of a large family 
is not necessarily lacking in a tough 
constitution which will enable him to 
survive for ninety years or more. 
As the number of children in the 
ranks beyond ten is too small to give 
reliable comparison, I have added these 
together to make one rank of eleven and 
more children. To facilitate compari- 
son, I have reduced the figures to a 
percentage basis, taking as the base- 
line in each birth-rank 100.4 We then 
get the following fair comparison of the 
proportion of long-lived people which 
the various birth-ranks have furnished: 
Lo eo ae Bee 152 
DO eta x aeons Sel cia 90 
SONNE ote ike. anie lk hiatal 86 
Rit wt eas wees ae 94 
Ware yeceale sc rans Sree os 100 
BEE ore P iti a sin Bk a hs 61 
Msi rece tab arciNs «Hager het 106 
GL ION Se foccts ane aahe aie 79 
~ eat a Stes rae 85 
MAVELS 5 So ceed are orks we eto 125 
LEED SHS up, e053 ood har 117 
The preponderance of first-born is 
still striking, but the high proportions 
in the last birth-ranks are somewhat 
unexpected. I think the latter situa- 
tion can be partly explained on statis- 
tical, rather than biological grounds. 
If a centenarian were the youngest of 
thirteen brothers and sisters, for in- 
stance, his descendants might well be 
struck by the fact and remember it; 
of Heredity 
therefore they would put it down in 
furnishing data to the Genealogical 
Record Office. If, however, their an- 
cestor were in the middle of such a 
family, there is slightly less likelihood 
that they would remember his exact 
birth-rank and therefore they would, ina 
greater number of cases, leave that 
blank unfilled when furnishing informa- 
tion. This is merely a conjecture, but 
seems to me sufficient to account for 
the presence of some of these late 
arrivals—whose absolute numbers, it 
must always be remembered, are very 
few. 
Will a similar supposition account for 
the presence of any of the first-born in 
the table? I think it very possible that 
relatives might more easily remember 
that Uncle Abner was the eldest son, 
than that he was fifth-born, in a family 
of nine. It may be, therefore, that we 
have in our statistics a greater number 
of first-born than an absolutely random 
sample of the population would furnish. 
But this appears to be a source of com- 
paratively small, if any, error, because 
the preponderance of the first-born is 
as striking in families of two and three as 
it is in some of the larger fraternities. 
Admitting that this may have con- 
tributed slightly to swell the number of 
first-born, I do not think it can reduce 
seriously the great preponderance—217 
out of a total of 802, if we include the 
sixteen who were an “‘only child.”’ This 
preponderance can be well shown in 
another way, by the percentage table on 
page 397, which Dr. Alexander Graham 
Bell prepared. 
The evidence appears to me conclu- 
sive that, among the long-lived people 
in the United States, eldest sons and 
eldest daughters are considerably more 
frequent than would be the case, if 
longevity had no connection with birth- 
rank. 
How can we square these results with 
those reported* by Karl Pearson: that 
still-births are most frequent among 
* The number found was multiplied by 100 and the product divided by the number expected. 
This device was used by Corrado Gini (JourNAL oF Herepity, Vol. VI, pp. 35-39, Jan., 1915) 
in showing that first-born were most frequent among the college professors of Italy. 
4 Pearson, Karl. 
wholly confirmed by other data, 
On the Handicapping of the First Born. London, 1914. Summarized in 
the JOURNAL OF HerepitTy, Vol. VI, pp. 332-336, July, 1915. 
Pearson's conclusions are not 
A. Ploetz, for example, found in 3,319 births in the German 
nobility, that there was very little difference in the percentage of deaths under 5 years, when taken 
