136 PRINCIPLES OF STOCK-BREEDING. 



in which the malformed being is stated to have been 

 a twin. Katsky, however, Nargele, and Saviard, have 

 each, as before stated, mentioned a case in which both 

 twins were hermaphroditically formed in their sexual 

 organs." 1 



It is worthy of mention, in this connection, that 

 some authors assert that the production of twins in 

 the human species is an abnormal peculiarity, and 

 they claim that a larger proportion of idiots and im- 

 beciles are twin-born than of those not thus affected, 

 that the relatives of imbeciles and idiots frequently 

 have twins, and that, in families where twins are fre- 

 quently produced, bodily deformities are repeatedly 

 observed. 9 



Dr. Duncan, in his work on " Fecundity, Fertility, 

 and Sterility," is inclined to the belief that the pro- 

 duction of twins in the human family is not only 

 abnormal, but that it cannot be relied upon as an indi- 

 cation of great fecundity, as twins are usually pro- 

 duced at longer intervals than single births, and that 

 in the latter the entire period of child-bearing is like- 

 ly to be more extended. 



1 Loc. dt., p. 736. 



a See Dr. Arthur Mitchell's paper in the Medical Times and Gazette, 

 November 15, 1862, referred to in Walford's "Insurance Cyclopedia," 

 vol. iii., p. 192. 



