REMARKS ON THE SO-CALLED MEDIASTINAL SEPTUM OF THE DOG, IN RELATION TO THE PNEUMOTHORAX PROBLEM IN MAN

It is a remarkable fact that after nearly half a century of animal experimentation, in which the dog has been utilized for the systematic study of the problems of intrathoracic surgery, a question so seemingly elementary as the anatomic unity or duality of the pleural cavities in this species should still remain a subject of discussion and controversy. That this is true is abundantly shown by the current literature and the animated discussions that we have heard today. We gather that a new interest in the comparative anatomy of the pleura, from the thoracic surgeon's point of view, has been roused and that many observations have been brought to light which have added to our knowledge of the subject. On the other hand, a certain number of theories have been advanced, here and abroad, by highly competent and trustworthy investigators, which flatly contradict one another, leaving the unprejudiced observer confused