314 Concluding Remarks 



other hormones which receive Httle attention I think their hormone 

 deserves more thought than we have given it. Among these other 

 hormones I would hke to mention perhaps the thyroid. In myxoe- 

 dema there is a profound alteration in water metabolism, and that 

 might have exercised our thoughts too. Growth hormone is another 

 one which may be very important in the development of some of the 

 responses which vary with age, particularly in the younger organism. 

 Finally, the data which Dr. Shock described to us and on which 

 Dr. Kennedy's experiments also have a bearing, raise the question, 

 not completely solved, of whether the variations in renal function 

 which occur in senescence are entirely due to the age changes in the 

 kidneys themselves, or whether they might also be partly influenced 

 by the changes in hormone levels at that age. I have in mind particu- 

 larly the altered relationship between the adrenal anabolic and cata- 

 bolic steroids, which apparently moves in favour of the latter. 



