[ 412 ] [Book IX. 



CHAP. XLIII. 



THE GROWTH AND DECLINE OF THE BODY. 



Increafe of the Bo dy btforg and aftzr Birth. Difproportitn nf the Parts 

 dscreafes 'with Growth, What Parts firft ceafe to increafe in Size. 

 Youth. Manhood. Fir/} Symptoms nf Decline. 'At what Period 

 old dge generally commences. Symptoms of Age.Caufts nuhy the 

 Human Frame cannot be of long Duration. 



FROM the time of conception till birth, the growth 

 of the body proceeds in an accelerated or in- 

 creafing proportion, that is, the growth in the fixth 

 month, for inftance, is greater in proportion than in 

 the fifth ; from birth tili manhood it is gradually lefs 

 and lefs, in other words, the growth of the fecond year 

 is lefs in proportion than that of the preceding, and fo 

 of all the fticcceding years. 



The reafon commonly affigned for the latter of 

 thefe facts is, that the fibre becoming lefs diftenfible 

 from an increafe of folidity as we advance in age, our 

 growth is confequently lefs rapid. But if the rapidity 

 of growth was proportioned to the laxity of fibre, the 

 foetus ought to increafe mcft rapidly immediately after 

 conception, and more (lowly as its texture becomes 

 more firm. The contrary of this, however, is found 

 to be the fact, fmce, in the early periods of geftation 

 the increafe of the foetus ib very (low, and its growth 

 is continually accelerated till the birth. From this 

 fbtement it muft be concluded, that laxity of fibre is 

 only one among other caufes which favour the increafe 

 of the body. As the body advances in growth, its 

 difprcportions are gradually loft; the head increafes 



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