Since the beginning of the present century, many workers have been interested in various aspects of insect nutrition. The early investigators were interested in the effects of bacterial action and consequently were led to investigate the effect of sterilization of both the experimental animals and the dietary substrate. Pasteur, although he never attempted to do so himself, once declared to the Academy of Science that he hoped to see a research worker attempt to rear an animal under strictly aseptic conditions. Much of the nutritional literature is concerned with a continuation of this argument. Even today, such eminent workers as Wigglesworth (93), Mansour (63) (64), and Koch (57) (580 (59) are unwilling to define the role played by bacteria in nutrition. Bacteria, regardless of their role, fall into two main categories: those contained in the food; and those living in the mycetomes, which in some cases communicate with the gut. The subject is important because of the fact that bacteria may be capable of fixing free nitrogen or of converting one type of amino acid to another. For very precise work, undoubtedly bacterial action is an important factor. However, in some cases, it is possible to neglect the question of the action of bacteria on the food. In the natural state, the food is certainly contaminated with bacteria, and under normal conditions, there is no such things as asepsis. [...]

Stanley, J. (Supervisor)