CHAPTER III. 



WEIGHT INCREASE OF DIFFERENT PARTS OF THE 

 BODY AND INCREASE IN STATURE. 



Tissue systems Weight changes Significance of changes in 

 proportion Weights of organs Number and size of elements 

 Hypertrophy and hyperplasia Statistical difficulties The 

 dead form a series different from the living Premaxima 

 Deviation from the mean Mortality curve Relation to the 

 statistics of weight Weight and longevity Growth an ex- 

 pression of vigour Stature Direction of. first growth Rate 

 of increase Rhythm of growth Relations of the divisions of 

 the day and year to growth. 



THE observations contained in the previous chapter 

 relate to the entire body, while here I shall introduce 

 facts bearing on some of its anatomical subdivisions. 

 For the purpose of this further study the entire body 

 may be resolved into the group of tissue systems which 

 compose it. Indeed it is almost necessary to approach 

 the subject in this way, because the different tissues, 

 of which the nervous system is one example, are so 

 mutually dependent upon one another for the manner 

 in which they develop, that important modifying 

 conditions are overlooked, when any one system is 

 considered alone. 



Histologists recognise in the body a series of struc- 

 tural elements, designated as epithelial, connective, 

 nervous, and muscular. From these, combined in 

 varying proportions, are built up the different organs 



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