TRANSACTIONS OF SECTION H. 



I I 



1 



citizen of the United States by his personal appearance, without being under the 

 necessity of waiting to hear his speech and intonation. 



It may perhaps be thought, in selecting the subject of Heredity for my address, 

 and in treating it as I have to a large extent done, in its general biological aspects, 

 that I have infringed upon the province of Section D. But I am not prepared to 

 admit that any such encroachment has been made. IMan is a living organism, 

 with a physical structure which discharges a variety of functions, and both struc- 

 ture and functions correspond in many respects, though with characteristic differ- 

 ences, with those which are found in animals. The study of his physical frame 

 cannot therefore be separated from that of other living beings, and the processes 

 which take place in the one must also be investigated in the otlier. Ilence we 

 require, in the special consideration of the pliysical framework of Jlan, to give due 

 weight to those general features of structure and functions which he shares in 

 commOQ with other living organisms. But whatever may have been the origin of 

 his frame, whether by evolution from some animal form or otherwise, we can 

 scarcely expect it ever to attain any greater perfection than it at present possesses. 



The physical aspect of the question, although of vast importance and interest, 

 yet by no means covers the whole ground of Man's nature, for in him we recognise 

 the presence of an element beyond and above his animal framework. 



Man is also endowed with a spiritual nature. He possesses a conscious respon- 

 sibility which enables him to control his animal nature, to exercise a discriminating 

 power over his actions, and which places him on a far higher and altogether dif- 

 ferent platform than that occupied by tlie beasts which perish. The kind of evolu- 

 tion which we are to hope and strive for in him is the perfecting of this spiritual 

 nature, so that the standard of the whole human race maybe elevated and brought 

 into more harmonious relation with that which is holy and divine. 



3. On the Early Failure of pairs of Grinding-Teeth. 

 By W. WiLBERFORCE Smith, M.D., M.B.C.P. Land. 



The author gave the results of the examination of 153 persons — all dwellers in 

 London, and composed of shop women, of physician's out-patients, and of a group 

 of young men forming a mutual improvement society. 



These results, tabulated below, tend to indicate that when the grinding-teeth, 

 premolars, and molars are considered as opponent pairs, the average loss is far 

 greater than casual observation of the fi-out of the mouth would be likely to 

 sugtrest, and tliat it progresses rapidly in young adults, pari jmssu with age, 

 Avhich is the essential modifying condition. 



The loss is much greater in molar than in premolar pairs of teeth, just as 

 premolars are in their turn more liable than front teeth (canines and incisors). 



These facts may be compared with various others tending to the conclusion 

 that the lessened wear and friction in the grinding-teeth of civilised races is a pre- 

 disposing cause of decay. 



Pairs of Molars. 



3 D 2 



