CONTENTS 



PAGE 



Advertisement iii 



Acknowledgment ix 



I. Introduction 1 



II. Summary of results 2 



General shape of the femur of the lower animals 'i 



Relation of structure to shape 4 



Density of bone 5 



Measurements 5 



Medullary index S 



Medullary canal 7 



Medullary contents 8 



Medullary surface 'S 



Cancellous bone and trabeculae 9 



Variety of minute structure of the wall of the femur 9 



Units of bone structure 10 



Bone cells, lacunae 1" 



Dendrites, canalicull 10 



Differentiated bone units — lamellte 10 



Uniformly lamellated bone structure 1 1 



Twofold division 1 1 



Threefold division • 11 



Laminae 1 1 



Haversian systems 1 1 



Types of bone structure 1"2 



First type 1- 



Second type 13 



Incomplete 14 



Complete 14 



Third type H 



Haversian system III la IS 



Haversian system III lb I-> 



Haversian system III Ic 10 



Haversian system III C 10 



Frequency of occurrence 1" 



Type combinations 1*^ 



Type of boue structure according to classes of animals 18 



Amphibians 1^ 



Reptiles 1 '' 



Birds !•' 



Mammals -0 



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 



:;. Sex 25 



4. Age -•' 



5. Function 26 



6. Individual variations 27 



7. Health and disease 27 



8. Heredity 27 



Conclusions - ' 



V 



