Neglected Areas of Nutrition Research 177 



because goldfish have long been pets, are easily cared for 

 and cheaply fed upon dry feed mixtures. Quite the contrary 

 is true for the various trout species with which we laboured 

 for so many years. They require special water conditions, 

 unique diets and are somewhat difficult to culture. 



Turtles, whose hearts we have all admired since our 

 earliest study of physiology, are deserving of the most intense 

 study. In spite of our admiration for their tough hearts, 

 little is known about the biochemistry involved. Turtles can 

 be hatched and reared in confinement. Two decades ago, in 

 a study that was never published, my associate J. B. Sumner 

 and I injected crystalline urease into the jugular of a snapping 

 turtle. Many times the amount was used that would kill 

 another species such as a rabbit but no level was found that 

 even annoyed the turtle. Later, we found the blood of the 

 turtle to be naturally quite rich in ammonia. Turtles, un- 

 doubtedly, know biochemical secrets about ageing that 

 might be useful to man. 



Finally, domesticated birds such as pigeons, chickens, 

 turkeys, geese and ducks offer special opportunities. Long 

 time study of any of these species would undoubtedly lead 

 to advances in the basic knowledge of gerontology and facts 

 that would have utility in practical poultry husbandry. 

 From the consideration of the span of life and old age diseases 

 little attention has ever been given to any of these species. 



As we look back over a quarter of a century, we believe if 

 we could have foretold the progress that was to be made in 

 the study of the genetics of the mouse that we would have 

 selected this species in preference to the albino rat. One of 

 the earliest demonstrations of the life span of a rodent was 

 made in a study of mice by Robertson and Ray (1920). 

 Likewise the very important observation that tumours could 

 not be implanted in partly starved mice was made by a 

 student of Ehrhch early in this century (Moreschi, 1909). 



Many thousands of mice are wasted each year in genetic 

 laboratories because the breeding animals are usually only kept 

 until early middle age. The great disadvantages of mice from 



