xiv CONTENTS. 



CHAPTER XIX. 



Teeatogenesis 605 



Malformations Involving More Than One Individual 605 



Classification, Description, Origin . . .... . 605 



Symmetrical Duplicity ... .... . . 606 



Origin of Symmetrical Duplicity . 611 



Asymmetrical Duplicity . . • 612 



Origin of Asymmetrical (Parasitic) Duplicity . . 614 



Malformations Involving One Individual . ... . . .616 



Description, Origin ... 616 



Defects in the Region of Neural tube . 616 

 Origin of Malformations in the Region of Neural Tube . . . .619 



Defects in Regions of the Face and Neck, and their Origin . . . 620 



Defects in the Thoracic and Abdominal Regions, and their Origin 622 



Malformations of the Extremities . 622 



Causes Underlying the Origin of Monsters 624 



The Production of Duplicate (Polysomatous) Monsters . 625 



The Production of Monsters in Single Embryos. . 626 

 The Significance of the Foregoing in Explaining the Production 



of Human Monsters. ....... ... 627 



References for Further Study 627 



Appendix. 



General Technic . 629 



Procuring and Handling Material . 629 

 Fixation ... .631 



Hardening 633 



Preservation . 633 



Embedding . 633 



Section Cutting 634 



Staining . . 635 

 Methods of Reconstruction . . . . -637 



References 638 



