176 



POULTRY DISEASES 



during development does not follow the normal 

 type, then malformations, as atresia, imper- 

 forate anus, or other natural openings may re- 

 sult ; abnormal position of viscera, a failure of 

 the closure of the abdominal or thoracic plates 

 may take place. 



The germ or embyro is first developed as a 

 manifold membraneous expansion, the free mar- 



FiG. 55. Monster Chick (dipygus tetrabrachiun) 

 Showing two bodies, four legs, four wings and 



one head. 



gins of which incline towards each other, and 

 eventually meet to form two cavities. A failure 

 to meet results in malformation. Fusion of parts 

 may also take place. 



Those malformations in which there are super- 

 numerary parts or duplications of almost an en- 

 tire body are sometimes called composite or com- 

 pound malformations and monsters. 



Hermaphroditism is a complete duplication of both male 

 and female genital organs; i. e., a single individual possessing 



