50 THE LUNGS, BY FRANZ EILHARD SCHULZE. 



cylindrical passages which terminate csecally after dividing 

 dichotomously at acute angles, from two to four times, at a 

 distance of 2 4 millimeters from each bronchial extremity. 

 They present small gradually expanding or funnel-shaped 

 terminal processes, and similarly pedunculated short lateral 

 branches, both of which, on account of their constricted 

 entrance and wide bases, are termed infundibula. [Openplexi- 

 form communications between adjoining air passages were first 

 erroneously stated to exist by Bourgery,* and subsequently 

 by Adrian/f Williams,:}: and others.] These passages, how- 

 ever, do not, like the bronchia, possess uniformly thick, solid 

 walls, but are beset with numerous small polyhedric cavities, 

 with rounded angles and borders, that are in immediate contact 

 with each other, and opening into the lumen of the passage are 

 called the alveoli. These are so closely arranged, both on the 

 lateral and terminal processes of the infundibula, that only an 

 extremely small portion of the parietes of the passages is formed 

 by the free borders of the septa of the alveoli, but in by far 

 the greatest part by the walls of the alveoli themselves. I 

 would therefore name them alveolar canals or passages. 



[Intralobular bronchial ramifications (Addison) ; lobular pas- 

 sages (Todd) ; intercellular passages (Rainey). Whilst according 

 to the more popular German text-books the infundibula con- 

 stitute the terminations of the divisions of the bronchia, I 

 find descriptions of the structure of the parenchyma of the 

 lung, similar to those which I have here given as the result of 

 my own observations, have already been published by Lere- 

 bouillet, Addison, 1 1 Rossignol,1T and Le Fort;** also (putting 

 aside the open retiform communications of the passages there 

 maintained) in the article by Dr. Williams, on the Organs of 

 Respiration, contained in Todd's Cyclopaedia of Anatomy and 

 Physiology, Vol. v., 1859 ; and by a few other English writers.] 



* Gazette des Hopitaux, Juillet, 1842. 

 f" De subtil, structura pulmonum, 1847. 

 Todd's Cyclopaedia of Anatomy and Physiology, Vol. v. 

 Anatomie Comparee de VAppareil Eespiratoire, 1838. 

 || Philosophical Transactions, 1842. 

 IF Eecherches sur la Structure intime du Poumon, 1846. 

 ** Eecherches sur V Anatomie du Poumon chez VHomme, 1859. 



