966 GROWTH AND THE AGING PROCESS I4, 



growth and senescence. We may ask ourselves whether, if such an important 

 relation exists between these two processes, the one may be altered experimentally 

 by altering the other. The evidence in this regard is extensive and, it would 

 seem, conclusive. Northrop (191 7) showed that prolongation of the period of 



Fig. 7A. Fatty degeneration in the parotid gland of a senile rat, a 700-day old female. 



X 106. 



Fig. 7B. Peculiar large cell or "oncocyte" in the parotid gland of a senile rat, a 1000-day 



male. X 10 14. (Figs. 7A and 7B after Andrew, 1956). 



growth in Drosophila resulted in prolongation of the life span. Jennings and 

 Lynch (i928a,b) and Ingle (1933) showed that semi-starvation of CWoc^ra pro- 

 longs the length of life. Kopec (1928) was able to generalize that in vertebrate 



