CONTENTS 



PAGE 



Advertisement iii 



Acknowledgment ix 



I. Introduction 1 



II. Summary of results 2 



General shape of the femur of the lower animals 3 



Relation of structure to shape 4 



Density of bone 5 



Measurements 5 



Medullary index 5 



Medullary canal 7 



Medullary contents 8 



Medullary surface 8 



Cancellous bone and trabecular 9 



Variety of minute structure of the wall of the femur 9 



Units of bone structure 10 



Bone cells, lacunas 10 



Dendrites, canaliculi 10 



Differentiated bone units — lamellar 10 



Uniformly lamellated bone structure 11 



Twofold division 11 



Threefold division 11 



Laminar 11 



Haversian systems 11 



Types of bone structure 12 



First type 12 



Second type 13 



Incomplete 14 



Complete 14 



Third type 14 



Haversian system III la 15 



Haversian system III lb 15 



Haversian system III Ic 16 



Haversian system III C 10 



Frequency of occurrence 17 



Type combinations 18 



Type of bone structure according to classes of animals 18 



Amphibians 18 



Reptiles 19 



Birds 19 



Mammals 20 



Bats 20 



Other mammals 20 



Man 21 



Fetal 21 



Adult 21 



Black 22 



Yellow-brown 22 



Ancient Egyptian, XII Dynasty 23 



Modern — white 23 



Factors influencing the structural types of bone 24 



1. Grade of animal in biological classification 24 



2. Geographical position 25 



3. Sex 25 



4. Age 25 



5. Function 26 



6. Individual variations 27 



7. Health and disease 27 



8. Heredity 27 



Conclusions 27 



v 



