J. PERCY BAUMBERGER 



INTRODUCTION 



Throughout the whole organic world the essential food element 

 most difficult to acquire is nitrogen, as all nitrogen must ulti- 

 mately come from the atmosphere and the power of combining 

 with this gas is limited to a few microorganisms. Upon the nitri- 

 fying bacteria, then, all higher plants and animals are dependent 

 for their nitrogen which is handed from one organism to another, 

 linking all together into one great interdependency which has 



Fig. 1 The nitrogen cycle (from Bayliss). The accessory lines and circles in 

 — - — - — are my additions based on evidence in this paper. 



been called the nitrogen cycle. I insert a diagram from Bayliss 

 w^hich clearly illustrates this cycle. The accessory circles and 

 the lines that connect them are additions based onmy expermients. 

 The search of the insect for nitrogen is very complicated and has 

 been, at times, obscure. Indeed, httle definite information is 

 at hand concerning the food requirements in general of these 

 organisms, as the material consumed is often in large part merely 

 the substratum for a small amount of assimilable food. This 

 has led to many misunderstandings as to the synthetic power of 



