470 



GENERATION. 



2. Desgranges observed another instance in 

 which a woman bore two girls at the interval 

 of a hundred and sixty-eight days in the 

 same circumstances as in the above-mentioned 

 case.* 



3. A third case is related by Fournier in 

 which two girls were born at the interval of 

 five months, there being lochia for a few days 

 after the birth of the first.f 



4. A fourth instance is mentioned of two 

 children born at the interval of a hundred 

 and nine days.J 



5. Velpeau relates that a Mad. Bigaux had 

 first a living child, and four and a half months, 

 or a hundred and forty days afterwards, a 

 second, also alive. 



We confess that we think these cases, if 

 correctly reported, go far to prove the possible 

 occasional occurrence of superfoetation in the 

 human species. On the supposition that two 

 children born alive at different periods remote 

 from one another have been conceived at the 

 same time, three months appears to be the 

 greatest extent to which the interval between 

 their births could reach, the first being born 

 prematurely at six and a half or seven months, 

 and the second being retained in the uterus 

 till the period of nine and a half or ten months ; 

 but this is improbable in some of the instances 

 before us, as both children appeared equally 

 complete, and no mere difference in the rate 

 of their growth could account for their birth at 

 so remote periods. 



We are reduced then to the necessity of ad- 

 mitting the possibility, in very rare instances, of 

 superfoetation ; but at the same time we may 

 remark that the evidence regarding it is not 

 sufficiently precise, and we are left entirely at 

 a loss to explain what causes may give rise to 

 this variation, and in what manner the seminal 

 fluid may be supposed to pass through the 

 uterus, or the new ovum to gain an entrance 

 there. 



2. Influence exerted by parents on the 



Stalities of their offspring in generation. 

 ne of the most obvious and important laws 

 of the reproductive function is that by which 

 the specific distinction of animals is preserved. 

 Like produces like ; and for the most part an 

 undeviating succession of generations of simi- 

 lar structure and qualities prevents both the 

 extinction of any species and its being blended 

 with or lost in any other. Numerous examples 

 will recur to the mind of every one, of striking 

 family resemblance, which point out in how 

 many respects children frequently inherit their 

 qualities from their parents ; but it must be 

 held in remembrance that family or hereditary 

 resemblance is seldom if ever complete, but 



* Diet, des Scien. Med. torn. liii. p. 418. 



t Ibid. torn. iv. p. 181. 



t Stark 's Archiv. fur die Geburtshulfe, &c. B. iv. 

 S. 589. 



Traite d'Accouchements, torn. i. p. 345, where 

 cases are referred to by Pignot in the Bull, de !a 

 Facult. 4e Annee, p. 123, by Wendt, Journal des 

 Progres, torn. x. and Fahrenhorst, ibid. torn. viii. 

 p. 161. 



only of that more general kind which belongs 

 to the species. Thus in one family we re- 

 cognise numerous minute differences, and in 

 fact it may be said that there are scarcely any 

 two individuals of the same or of different 

 family exactly alike. In respect to sex, the 

 most obvious difference exists : the mother 

 producing male and female; the son is not an 

 exact copy of his father, nor the daughter of 

 her mother, nor are they a mixture of both ; 

 but each of them bears certain resemblances to 

 one or other or to both of the parents, into 

 which it may be interesting to inquire, an in- 

 vestigation which is to be regarded of some 

 practical importance in reference to the breed- 

 ing of cattle and other stock. 



As the female parent furnishes the greater 

 part of the substance of the egg in all animals, 

 and in viviparous animals provides also the 

 materials which serve for the nourishment of 

 the young with which it is intimately con- 

 nected during utero-gestation, it might, a priori, 

 have been supposed that the offspring should 

 be more subject to be influenced by the qua- 

 lities of the mother than by those of the father ; 

 but no general fact of this kind is established, 

 and instances need not here be adduced which 

 shew that the offspring, whether male or fe- 

 male, bears nearly, if not quite, as many 

 points of resemblance to the father as to the 

 mother. 



Such influence as the male parent exerts 

 upon the qualities of the offspring must be 

 transmitted and take effect at the period of 

 conception only, and the impression being 

 that of the contact of the seminal fluid with 

 the ovum must be momentary only. A cer- 

 tain part of the female parent's influence is 

 dependent on the original constitution of the 

 ovum formed in her body, while another part 

 of that influence may be supposed to extend 

 through the whole period of utero-gestation. 



We shall first consider those instances of 

 the transmission of hereditary qualities which 

 appear to belong to the original constitution 

 of the male and female generative products, 

 and subsequently make some remarks on the 

 influence which the female has been held to 

 exert during the whole of pregnancy. 



The general structure of the body, the sta- 

 ture, form, size of the bones, disposition to 

 the formation of muscle, deposition of fat, or 

 the reverse, seem to depend as frequently on 

 the female as on the male parent in the human 

 species. In some animals the male parent 

 more frequently determines the size and general 

 form of the body, as among feline animals, 

 dogs, horses, &c* The bantam cock is said to 

 cause the common hen to lay a small egg, and 

 the common cock causes the bantam hen to 

 lay a larger egg than usual. 



An enumeration of all the points of struc- 

 ture which constitute family resemblance would 

 detain us too long, and is unnecessary as they 

 are familiar to every one. It does not appear 

 to be satisfactorily established that the family 

 resemblance is derived more from one than 

 from the other parent, though in one family 

 the influence of the one parent, and in another 



