PROPORTIONAL GROWTH. 271 



Arthur and John ; the ratio of the quantity of 

 growth, and the size which indicates the result 

 of growth, in the head as compared with the body 

 is identical in each man. 



When we speak of equal or good proportion, 

 or otherwise qualify the kind of proportion, we 

 are in reality considering at least four things. Thus, 

 when I say that a child's head is in good propor- 

 tion, I compare the size of its head with the size 

 of its body, and then compare this ratio with the 

 ratio of the head and body in a perfect child. 



Equal proportional growth. This term is con- 

 venient, but it requires explanation. The meaning 

 of "proportional growth" has been explained. It 

 was found that the term was applicable to two 

 subjects : it concerns the ratio of growth, and 

 denotes the proportion of the quantity of the 

 growth in the one subject to the quantity of growth 

 in the other subject. 



The term " equal proportional growth " implies 

 that two ratios are equal. Two subjects, each pre- 

 senting two similar parts for comparison, are here 

 referred to; the ratio of the quantity of growth 

 in the two parts of the one subject is said to be 

 equal to the ratio of the quantity of growth in 

 the two corresponding parts of the other subject. 



" In Arthur and John the proportional growth of 

 the head and body were the same." J. 1 



The, quantity of growth in the head and body 

 of each man was observed ; it then appeared that 

 the ratio of the quantity of growth of head and 

 body in each was the same. 



