398 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1913. 



difficult care of the sick or injured, the dressing of wounds, the 

 groans of those operated upon, or the death rattle of the dying. I 

 recall that several of your members are at this moment on the field of 

 battle, and have no fear of facing climatic danger's and enduring 

 hardships even unto death. 



You know that the laws of heredity are susceptible of happy appli- 

 cations in the human species, so that you will not doubt, I am sure, 

 some explanations that I shall give as briefly and as clearly as it is 

 possible for me to do. 



Heredity. What is meant by that word? You know what it is. 

 It is a fact of daily occurrence, that the descendants reproduce more 

 or less completely certain peculiarities which existed in one or the 

 other of their ancestors. 



There is right here a point of observation so universal, so generally 

 known, that it is never overlooked, after the birth of a new-born 

 child, to ask who it resembles. Is it the father? Is it the mother? 

 Generally, persons who have known the father as a child are of the 

 opinion that the newly born is exactly like its father at the same age. 

 On the other hand, those who knew the mother do not hesitate to say, 

 '' But no ; that little mouth, those large eyes, are they not its mother's? 

 There is a most striking resemblance.'' In reality both of these ob- 

 servations are correct, and we shall see that mathematically the child 

 has exactly one-half of the characteristics coming from the paternal 

 and one-half from the maternal line. If, in certain cases, very rare, 

 however, the child seems to have inherited more from one side than 

 the other, it is because certain characteristics are susceptible of re- 

 maining latent, masked, invisible; but they exist none the less, and 

 generally these latent characteristics include some paternal and some 

 maternal characteristics, so that in the great majority of cases the 

 child after all is an equal mixture of both parties, a mixture some- 

 times happy, sometimes, alas, unfortunate. It is these unfortunate 

 cases that a knowledge of the laws of heredity may in some degi'ee 

 restrain. 



Heredity bears not only on the features but on the physical char- 

 acteristics, the build, weighty tints of the skin, the eyes, the hair, etc. 

 It rules also the intellectual side, the morals, morbidness, etc. — ^in a 

 word, all that constitutes individuality. 



Certain individual characteristics may be transmitted for many 

 generations. The ancients have preserved to us the history of this 

 transmission in the Cicero and Lentulus families by some marks on 

 their countenances, to which they owe their name (" cicer," chick- 

 pea; "lentulus," lentil). In the same way a lock of white hair at 

 the middle of the forehead of the youth was for a long time trans- 

 mitted, they tell us. in the familj'^ of the Rohans. But these family 

 characteristics are not long in disappearing, which can be understood, 



