478 



GENERATION. 



rating, the application of the mother's hand to 

 any part of her own body will cause a dis- 

 figuration or specific impression on a corres- 

 ponding part of the body of the child." 



3. Number of children ; and relative 

 proportion of the male and female sexes. 



The simpler animals are, generally speaking, 

 more fruitful than the complicated ones. As 

 examples of great fecundity, may be mentioned 

 some of the Entozoa and Mollusca, which pro- 

 duce hundreds of thousands of ova ; among 

 Crustacea and Insects some produce many 

 thousand young. The Perch and Cyprinus 

 genus among fishes produce some hundreds of 

 thousands, and the common Cod, it is said, 

 some millions of ova. Most of the Batrachia 

 produce at least some hundreds. But in the 

 warm-blooded Vertebrata, the necessity of in- 

 cubation or utero-gestation puts a limit to the 

 number of young ; and there are also compara- 

 tively few in the Blenny, Skate, Shark, Land 

 Salamander, or such animals as are ovo-vivi- 

 parous. 



In the human female, the number of chil- 

 dren altogether produced is limited, first, by 

 the number of Graafian vesicles in the ovaries, 

 which usually amounts to from twelve to fif- 

 teen in each ovary ; and second, by the length 

 of the time during which a woman bears chil- 

 dren, (the greatest extent of which is usually 

 twenty-five years, that is, from the age of fifteen 

 to forty, or twenty to forty-five,) the length of 

 this period again depending upon the rapidity 

 with which the births succeed one another, and 

 the number of children produced at each. 



Women most frequently bear every twenty 

 months, but some have children at shorter in- 

 tervals, as of fifteen or even twelve months. 

 This often depends upon the circumstance 

 that in some lactation prevents conception; 

 in others it does not. 



The number of the eggs of birds for one in- 

 cubation varies from two to sixteen. The num- 

 ber of the young of Mammalia produced in 

 one utero-gestation varies from one to fifteen, 

 and occasionally more. 



Woman usually bears a single child. The 

 proportion of twin-births to those of single 

 children is estimated by Burdach as one to 

 seventy or eighty : the proportion of triplet 

 births one to six or seven thousand ; quadru- 

 plets, one to twenty or fifty thousand. Occa- 

 sionally five children come at one birth, and 

 there are instances on record of six or even 

 seven children being born at once. 



The causes of this greater or less fecundity 

 are not known : they are in all probability 

 various; being not of an accidental nature, 

 but connected with the constitution of one 

 or other of the parents, most frequently per- 

 haps of the mother. 



A healthy woman bearing during the whole 

 time, and with the common duration of inter- 

 val, may have in all from twelve to sixteen chil- 

 dren ; but some have as many as eighteen or 

 twenty ; and when there are twins, &c. con- 

 siderably more, as in the following remarkable 

 instances. First, eighteen children at six births. 

 Second, forty-four children in all, thirty in the 



first marriage, and fourteen in the second ; and 

 in a still more extraordinary case, fifty-three 

 children in all in one marriage, eighteen times 

 single births, five times twins, four times tri- 

 plets, once six, and once seven.* 



Men have been known to beget seventy or 

 eighty children in two or more marriages, but 

 the tendency of polygamy is generally believed 

 to be to diminish rather than to increase the 

 number of the whole progeny. 



According to Marc, not more than two or 

 three children are born from two thousand pros- 

 titutes in the course of a year, a circumstance 

 depending in part on their want of liability to 

 conception, and in part on frequent abortion. 



The proportion of children born in each mar- 

 riage varies much in different countries. The 

 following statement of the average number is 

 taken from Burdach : Germany, 6 8 ; Eng- 

 land, 5 7 ; France, 4 5 ; Spain and Italy, 

 2 3.f 



In reference to the average proportion of male 

 and female births, it appears from very exten- 

 sive data that in this and most other countries 

 the number of males usually exceeds that of 

 females ; in this country in the proportion of 

 four or five in a hundred. 



The circumstances which influence the pre- 

 ponderance of male births are not known. The 

 accompanying table shews how very constant 

 it is in different countries. 



Table of the proportional number of males 

 and females born in different countries ; the 

 females being taken as 100. 



Great Britain ............ 104.75 



Sweden .... ............. 104.72 



Wurtemburg ........ .. 105.69 



Westphalia and Rhine ____ 105.86 



Bohemia ................ 105.38 



Netherlands .............. 106.44 



Saxony and Silesia ........ 106.05 



Austria .................. 106.10 



Sicily ................... 106.18 



Brandenburg ............ 106.27 



Mecklenburg ............ 10707 



Mailand ................ 107.61 



Russia .................. 108.91 



Jews in Prussia .......... 112. 



- in Breslau .......... 114. 



- in Leghorn .......... 120. 



Christians in Leghorn ...... 104. 



It has been found, on the other hand, that the 

 first children of a marriage consist of a greater 

 number of females and fewer males, in the pro- 

 portion, according to Burdach, of fifty-three 

 male births to a hundred females. A similar 

 preponderance of females is said to exist among 

 illegitimate children ; but the difference is 



* See Foamier, Diet, des Scien. Mcd. torn iv. 



t According to Burdach, one marriage out of 

 fifty is unfruitful ; there is one birth on an average 

 for every twenty-five of the population of a place ; 

 and taking the whole population of the world at six 

 hundred and thirty-three millions, about fifty-one 

 children are born every second ! 



