xii CONTENTS. 



CHAPTER XIX. 



TERATOGENESIS 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 620 



Procuring and Handling Material '. 629 



Fixation 631 



Hardening 633 



Preservation 633 



Embedding 633 



Section Cutting 634 



Staining - 635 



Methods of Reconstruction . . '. 637 



References 



638 



