177 



It is simple, now that the exact relation of the lung to the thoracic 

 Avail in the elephant is known, to realise how Watson was misled. But 

 at the time of my dissections I only knew that his work harmonised ill 

 with the observations of previous authors already quoted. It is 

 interesting to note that Morrison Watson was also indebted to 

 Messrs. Jennison for at least one of the elephants on which he worked. 

 It was the knowledge that Watson had allowed the presence of a 

 pleural cavity, and a natural respect for the opinion of such an ex- 

 perienced observer which led me to consider the possibihty of patho- 

 logical change being the cause for the absence of a cavity according 

 to the accounts of so many other anatomists. 



My effort to prove the presence of pathological change was not- 

 only devoid of success, but convinces me that Watson's observation 

 was misleading. 



In my specimen the character of the connective-tissue, its uniform 

 density and thickness and the perfectly healthy state of the lungs all 

 pointed to a normal condition. When however, the lungs were remo- 

 ved from the chest it would have been difficult, without a micro- 

 scopic examination, to affirm that the smooth surface of the viscera 

 was not due to endothelial covering. 



The assertion that there is no pleural cavity in the elephant 

 might still be open to doubt if only adult specimens had been examined. 

 But the case of Miall and Greenwood (3) is that of a young female 

 about five feet high, in which it might reasonably be expected that 

 pleural adhesion of so extensive a character would not have occurred. 



Moreover Goldschmidt had the opportunity of dissecting a new- 

 born Indian elephant (8) and he found in it that there was no trace 

 of a pleural cavity. 



While dissecting the fresh carcase, being still loth to accept 

 the view^ that no pleura was present, it occurred to me that if such 

 were the normal condition, the lungs being held open, as it were, by 

 the adhesion to the thoracic parietes and the diaphragm, there would 

 be no tendency on the part of the bronchi to collapse. If such were 

 the case, as the argument presented itself, there would not seem to be 

 the need for the intrapulmonary bronchial cartilages such as are 

 found in other mammals. 



Not knowing at the time that observations had already been 

 made (3) (5) on this point, I dissected the bronchial system and could 

 not find, by either macroscopic or microscopic methods, any trace 



Anat. Anz. Bd. 44. Aufsätze. 12 



