CONTENTS 



Page 



Introduction i 



I. Development and evolution of the head 3 



II. General external structure of the insect head 1 1 



III. The so-called "sutures" and the surface areas of the head IS 



IV. The posterior head structure 21 



V. The antennae 28 



VI. The tentorium 32 



VII. Theoretical considerations 38 



The labrum 39 



The embryonic head lobe 45 



The antennae 51 



Lettering on the figures 55 



References 56 



