ON THE HISTOLOGICAL STRUCTURE 

 OF CETACEAN LUNGS 



By F. Haynes, m.a. 



and 

 Alec H. Laurie, m.a. 



(Plate I) 



THE peculiar structure of whale lungs was briefly mentioned in a report on respira- 

 tion in whales (Laurie, 1933, p. 370) wherein the great quantity of elastic tissue in 

 the lungs of two species of whale was illustrated by photomicrographs. Subsequently 

 further collections of lung tissue were made, particular attention being paid to the 

 freshness of the material. It is not always easy to obtain fresh specimens because of the 

 time that must elapse between the harpooning of the whale and its dismemberment at 

 the whaling station. Sections of lungs have been prepared and stained with Haema- 

 toxylin-Eosin and Weigert-Van Gieson. We are indebted to Mr Steggall, assistant at St 

 Bartholomew's Hospital Medical School, for sectioning and staining the material. 

 Lung samples from the following species have been examined : 



Fin Whale {Balaejioptera physa/us), 

 Humpback [Megdptera nodosa), 

 Sperm Whale {Physeter catodon), 

 Southern Right Whale {Balaena aiistralis). 



In Plate I (Figs. 1-5) an attempt has been made to show the stained sections as nearly 

 as possible as they appear under high-power magnification. Diagrammatical represen- 

 tation was felt to be undesirable in depicting structures which have been found to 

 show some departures from the usual mammalian form. We are indebted to Professor H. 

 Hartridge, F.R.S., for kindly allowing us to use the micro-projector which he has de- 

 signed for histological studies. This instrument allows a highly magnified image of the 

 specimen to be thrown on a sheet of paper or Bristol-board, thus facilitating an accurate 

 copy. Figs. 6 and 7 were drawn from direct observation by Haynes, using a 1/12 in. 

 objective, since it was impossible to project an image of such magnification owing to 

 illumination difliculties. 



Gross structure of lungs. Before dealing with the stained preparations, a few 

 words may be said about the gross structure of whale lungs. All the species examined 

 show certain features in common. Chief among these is the thickness of the pulmonary 

 pleura, which consists mainly of elastic fibres laid down in much greater profusion than 

 is ever found in the lungs of terrestrial mammals. The pleura varies in thickness in 

 different species, but the average thickness has been found to be of the order of 5 mm. 



