CHAPTER 7 



GROWTH OF PARTS AND ORGANS IN RELATION 

 TO BODY LENGTH AND IN RELATION TO AGE 



1. Introduction. 2. Methods of examination and graphs. 3. Body length 

 on body weight. Body weight on body length. Tail length on body length. 

 4. Organs with an early rapid growth: Brain, spinal cord, eyeballs. 5. Organs 

 with a nearly uniform growth: Heart, kidneys, liver, spleen, lungs, blood, ali- 

 mentary tract, thyroid, hypophysis and suprarenals. 6. Organs with a rapid 

 growth just preceding puberty. Ovaries, testes, thymus (on age). 7. Determi- 

 nations of variation. 8. General tables, a) Tables, weight of entire body on 

 age. Before birth; from birth on. b) Tables, increase in the length and weight 

 of parts and organs on body length. 9. Table, weight of thymus on age. 10. 

 Table, weight of all viscera combined. 11. Tables, values for characters linked 

 with age. 12. Formulas. 



1. Introduction. The organs, the growth of which has been 

 followed are tail (length), brain, spinal cord, eyeballs, heart, 

 kidneys, liver, spleen, lungs (blood), alimentary tract, testes, 

 ovaries, hypophysis, suprarenals, thyroid and thymus. 



All the observations were made on stock Albinos from the colony 

 at The Wistar Institute, except those for the total blood which are 

 based on the records of Chisolm, '11. 



The mean values for the several organs were in each instance 

 charted and with these as a guide a theoretical graph was found 

 which could be expressed by a formula or a series of formulas. 

 All the formulas were devised by Hatai. 



To present the results in a convenient form the organs are 

 grouped in the text according to the manner of their growth, 

 each organ is accompanied by a chart showing the original data 

 and the graph based on these data. 



In each case reference is made to the formula or formulas on 

 which the graph is based, but as a matter of convenience, the 

 formulas utilized here for the graphs are grouped in the section 

 entitled "Formulas" pp. 158-175. 



86 



