Abstract
A two-headed calf had doubled heads and necks, externally normal forelimbs and thorax, incompletely doubled hearts and lungs, and a persistent sinus venosus, with abnormal pulmonary and systemic circulation. Study of the specimen indicated that partial twinning involved the development of the notochord as an anteriorly branched structure, with retention of the single condition posteriorly. It is proposed that anteroposterior compression of the embryonic disk could have induced the formation of double notochords. The way in which compression was produced is suggested.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
