560 



The Journal of Heredity 



incisor is located. This is the weak 

 point because of orthognathism, and 

 because of the tendency of the maxillary 

 arch to become constantly more acute. 

 The phenomenon appears as a form 

 of transition, in the subject which I 

 examined, because one of the incisors 

 is lacking and the other very slightly 

 reduced in size, while the teeth between 

 seem to attempt to compensate, by 

 their notable increase in size, for the 

 inadequate development of the laterals. 

 To confirm this idea, it is sufficient to 

 record an easily observed fact, and that 

 is the frequency with which, in the 

 skulls of civilized peoples, the upper 

 medial incisors appear much enlarged 

 and those beside them much reduced, a 

 difference which is also observable in 

 the skulls of prehistoric peoples. This 

 morphological condition is an indica- 

 tion of the modified functional condi- 

 tions to which man's teeth are subjected 

 in comparison to those of the other 

 vertebrates nearest to him in anatomy 

 and relationship. The function of the 

 incisors is essentially the seizing of 

 food, and particularly the separation 

 (tncidere) of the part which is to be 

 taken in the mouth, from that which 

 remains in the hand; this function is 

 preceded and then assisted to the highest 

 degree by the canine teeth, which have 

 to sieze and hold the prey during the 

 time necessary for the incisive opera- 



tion; the canines also have a special 

 function as a weapon of offense and 

 defense. In man this last function of 

 the canines is abolished, while that of 

 seizing is largely reduced in importance, 

 particularly among civilized peoples; 

 for these reasons the canines no longer 

 project below the plane of the other 

 teeth, and to that extent lose the char- 

 acteristic pointed form which they have 

 in other genera of vertebrates. When 

 man eats, he first divides the food for 

 chewing, principally by the use of his 

 medial incisors and to a less extent 

 with the lateral incisors; and particu- 

 larly with those of the upper jaw, since 

 it projects forward of the lower one. 

 The food is then pushed into the mouth 

 for mastication, and from then on the 

 work of the lateral incisors and canines 

 is very slight. The width to which 

 man opens his mouth is small in com- 

 parison with its aperture, and in com- 

 parison with the habit of other verte- 

 brates; this is because of his orthogna- 

 thism or lack of "muzzle" and because 

 of a diminution of his voracity, which 

 leads him to introduce into his mouth 

 only a small quantity of food at one 

 time ; these facts favor the action of the 

 medial incisors and diminish the impor- 

 tance of the other incisors and the 

 canines; the result is that the superior 

 lateral incisors are now an organ sub- 

 sidiary to the medials. 



The Justification for Eugenics 



Individuals a])pear to me as partial detachments from the infinite ocean of Being, 

 and this world as the stage on which Evolution takes ]jlace, ])rincipally hitherto 

 by means of Natural Selection, which achieves the good of the whole with scant 

 regard to that of the indi\'idual. 



Man is gifted with ]jity and other kindly feelings; he also has the power of pre- 

 venting many kinds of suffering. I conceive it to fall well within his province to 

 replace Natural Selection by other processes that are more merciful and not less 

 effective. 



This is precisely the aim of Eugenics. Its first object is to check the birth-rate 

 of the Unfit, instead of allowing them to come into being, though doomed in large 

 numbers to ]:)erish jjrematurely. The second object is the imi)rovement of the race 

 by furthering the ])roductivity of the Fit by early marriages, and healthful rearing 

 of their children. Natural Selection rests upon excessive j^roduction and whole- 

 sale destruction ; Eugenics on bringing no more individuals into the world than can 

 be properly cared for, and those only of the best stock.- -Francis Galton: Conclu- 

 sion to Memories of My Life (1908). 



