68 THE GROWTH OF THE BRAIN. 



nervous system to the body at large may be similarly 

 described. That a normal relation between growing 

 parts and the central system is necessary to their mutual 

 development is certain ; but whether through the nerves 

 the part under control directly receives anything more 

 than the stimuli which keep it in a state of healthful 

 excitement, and so enable it to make the best use of the 

 surrounding lymph, is an open question. However this 

 may be, the relative bulk of the central nervous system 

 has strikingly diminished in the adult as compared with 

 the new-born. 



As bearing on the proportional development of the 

 body, the observations of Bischoff have been quoted, 

 and though at present they represent the best part of 

 our meagre knowledge of this subject, yet in the future 

 we must hope to learn something of the effect upon the 

 various systems of the conditions which are found to 

 influence the growth of the body as a whole. All the 

 older data have also been collected by Vierordt, and 

 to his various tables the reader is referred. 1 The fore- 

 going table has also made plain that the several tissues 

 and organs increase in weight in very different propor- 

 tions. Among these, the viscera of the trunk make but 

 a poor showing, being proportionately much diminished 

 in the adult ; yet we have rather extensive data on the 

 change in the weight of the several viscera, and these 

 are worth examination. 



The facts bearing on this line of investigation 

 have been put by Vierordt 2 in the form of tables, 

 which are given below. Though the organs involved 

 amount at birth to only about 20 per cent, of the 

 weight of the entire body, more than half of which is 

 represented by the brain, and though they all belong to 



1 H. Vierordt, Daten und Tabellen, 1893. 



2 H. Vierordt, Arch.f. Anal, and PhysioL, 1890. 



