174 C. M. McCay 



fields as physiology, bacteriology, zoology, and entomology. 

 Only during the last quarter of a century even in the field of 

 nutrition has tliis climate of attitude clianged. 



Respect for comparative biochemistry and nutrition lirst 

 came from agricultural science in which men were accustomed 

 to thinking of the common species of domestic animals. 

 Since the early nineteenth century and the gelatin experi- 

 ments of Magendie the science of nutrition from medical 

 schools has rested heavily upon the dog and to a lesser extent 

 upon the mouse, rabbit and rat, towards the close of the 

 nineteenth century. 



However, only during the past thirty years has the bio- 

 chemist who works upon bacteria become respectable and 

 the one who devotes his love to insects or to any except a 

 selected few of accepted vertebrates is a subject for humour 

 and contempt if not suspicion. I have never forgotten the 

 peculiar expressions on the faces of my friends on both sides 

 of the Atlantic when they used to come to watch me weighing 

 my cockroaches, or my trout in the fish hatchery. Fish have 

 now become accepted fodder for the mill of the nutritionists 

 but insects are still not taken seriously as a form of life whose 

 biochemistry or gerontology may be worthy of study. 



If one indulges in some retrospect in regard to the discovery 

 and isolation of the vitamins, one must wonder how much 

 more rapid might have been the progress if biochemists 

 had neglected their mice and rats, and given all their devption 

 to micro-organisms and insects (McCay, 1953). In the case 

 of the water soluble vitamins substantial progress would 

 have been assured, but for the fat soluble vitamins there 

 might have been little progress. No insect has been discovered 

 thus far that needs either vitamin A or D, although there 

 may be many insects that need these factors and have never 

 been studied. If man had rested his nutritional science upon 

 insects we would probably be reading in the modern works 

 about human nutrition that each of us should consume so 

 many grams of cholesterol daily because this does seem to be 

 an essential for insects. 



