298 



The Journal of Heredity 



The size of the famihes of the iirst 

 three generations is obviously of little 

 signiticance on account of the small 

 number of individuals included. The 

 numbers in the following generation 

 rapidly increased. The fourth genera- 

 tion contains 23 families; the fifth, 52; 

 the sixth, 121 ; the seventh, 275, show- 

 ing that the number of fertile unions 

 more than doubled in each generation. 

 About the same rate of increase is 

 shown by counting the total number of 

 children of these families, which are as 

 follows: Thirty in the third, 155 in the 

 fourth. 359 in the fifth. 864 in the sixth, 

 and 1,760 in the seventh generation. 

 The average number of children per 

 family in successive generations is 

 shown in the table (see appendix). 



The ninth generation comprises peo- 

 ple whose parents lived for the most 

 part in the first half of the nineteenth 

 century. Their birth rate corresponds 

 roughly to that of the parents of ex- 

 isting Mayflower descendants from 

 whom we have received returns from 

 our questionnaires. 



DECLIXK IS RECIiXT 



The evidence froni the two sources 

 we have considered indicates that the 

 birth rate has been falling more or less 

 for the last 100 years, but the rate of 

 fall has been more rapid in the latter 

 half of this period. This is what one 

 would expect in the light of the general 

 decline of the birth rate, especially 

 among people of fairly high social 

 status. 



It must be admitted that the mem- 

 bers of the Society of Mayflower 

 Descendants represent a more or less 

 selected body of individuals, and that 

 if all the descendants of the original 

 band of Pilgrims were investigated, the 

 average birth rate would be found to 

 be somewhat higher. It is also possible 

 that the birth rate among members of 

 the California branch may be somewhat 

 lower than it is among those residing 

 in other states, but, however this may 

 be, there is little likelihood that the 

 birth rate of the entire group would 



come near being sufficient to insure the 

 propagation of the stock without loss. 

 The results we have obtained are 

 quite comparable to those of several 

 other studies on the decline of the birth 

 rate among people of American Ijirth. 

 The average family of the present May- 

 flower descendant is comparable in size 

 to the families of the graduates of Har- 

 vard, Yale, and other universities and 

 colleges, and to the families of Ameri- 

 can men of science studied by Cattell. 

 These families average somewhere be- 

 tween 2 and 2 5/10 children per married 

 couple, which is a somewhat better 

 showing than is made by the modern 

 descendants of the Pilgrim Fathers. In 

 fact, the average family of American- 

 born parents, judging from all the data 

 that have been collected on the subject, 

 contains somewhat less than three chil- 

 dren. With our present birth rate and 

 marriage rate, nearly four children per 

 married couple are required to per- 

 petuate the stock without loss. It is 

 evident that the people who are of 

 American lineage for more than two 

 generations are not reproducing with 

 sufficient rapidity to rescue their stock 

 from ultimate extinction. 



Mayflower's capacity 

 The data we have collected on the 

 birth rate of the Mayflower descendants 

 point to but one conclusion. With the 

 present rate of reproduction there must 

 be going on a rapid diminution in the 

 number of this once rapidly multiply- 

 ing band. To judge from the evidence 

 in our possession, their rate of multipli- 

 cation is scarcely one-half what it should 

 be to keep the stock even stationary. 

 This means that four generations would 

 affect a reduction to 1/16 of its present 

 numbers, and that in four more genera- 

 tions there would be only one represen- 

 tative to every 256 at the present time. 

 We shall soon celebrate the 300th an- 

 niversary of the landing of the Pil- 

 grims, but if their ])resent birth rate 

 continues for another 300 years, it 

 would probably be possible to put all 

 the surviving descendants back again 

 into the Mavflower without overcrowd- 



