RESPIRATION, ORGANS OF. 



will be found on the structure of the lungs. 

 The works of the Wiirzburg Professor 

 (Kolliker) contain the most recent, and 

 probably the most conclusive and important, 

 researches upon this subject. * In the details 

 which are now to follow reference will be fre- 

 quently made to the views taught by this 

 distinguished anatomist. 



Fig. 211. 



A. group of lobules loosened from their mutual attach- 

 ments, indicating the mode in which each lobule (b) 

 receives a single bronchial tube (a). (Original.) 

 Ate is represented the dichotomous manner in 

 which the primary and secondary orders divide ; at 

 c, d, and/, is shown the irregular arborescent method 

 in which the terminal lobular bronchi project from 

 every side and point of the circumference of the 

 secondary bronchial tubes. 



Minute Anatomy of the Lobule. The proper 

 pulmonary tissue (b,fig. 2 \ 1.) begins where the 

 bronchial tubes (a, fig. 211 .),end. The latter are 

 convective channels,and fulfil only a mechanical 

 purpose; the former is the immediate seat of the 

 respiratory process. These two parts differ no 

 less in anatomical structure than in mecha- 

 nical conformation. The bronchi terminate 

 in the " intralobular bronchial ramifications " 

 (Addison) ; lobular passages" (Todd) ; "in- 

 tercellular 'passages" (Rainey); "mouths of 

 the infundibula" (Rossignol). These are 

 different designations only for one and the 

 same thing. The passages in which the bronchi 

 end are greater in diameter than the bronchi 

 themselves. Their sides are at first smooth (), 

 like those of the bronchial tubes ; they become 

 afterwards loculated (c) with cells or alveoli, 

 like the terminal air-cells (e, b) (vcsicute s. 

 celluke aerecB s. Malpighiancs^ alveoli pulmonum 



* Mikroscopisch-Anatomie, Sweiterbund, Leipsic, 

 1850, and Handbuch der Gewebelehre des Men- 

 schen, von Kolliker, Leipsic, 1852. 



Rossignol. Lufizelkn oder Lungenbl'dschen of 

 the German writers). Looking down along a 

 section through one of these passages, it is 

 perfectly easy to define either an " infundibu- 

 lum," or a broad-based passage bounded by 

 Malpighian cells. It is, however, perfectly 

 certain that Rossignol has given in his illus- 

 trations far more regularity of outline to these 



Fig. 212. 



(After Hurting.') 



a is the termination of a bronchial tube properly 

 so called, ending abruptly in an intercellular pas- 

 sage marked by its cellulated parietes. I, e, cell- 

 tissue. 



parts than they present in the actual prepara- 

 tion. The intercellular passages (Rainey), 

 then, are those continuous channels in the 

 lobule which are laterally sacculated by 

 cells. They conduct the air to and from 

 every part of the lobule. They give rise to 

 secondary passages (b, e, j%.208.), which again 

 lead to a third, &c., all communicating with a 

 group of air-cells. Each of these passages 

 with its appended system of cells, if bounded 

 by an imaginary outline, may certainly be called 

 an " infundibulum." The intercellular passages 

 unite and divide (a, fig. 210.). They thus inter- 

 communicate. In this particular they are 

 distinguished from the bronchial tubes (b, 

 fig. 210.; c,fig. 212.), which never inosculate. 

 The latter are merely convective passages ; the 

 former are expressly organised for the office 

 of respiration. The bronchi diminish in ca- 

 libre as they divide ; the intercellular passages 

 rather enlarge in diameter (f,fig. 213.). The 

 former preserve in their branchings one main 

 direction ; the latter run through the lobule at 

 every angle. They are perforated at every point 

 by secondary passages (a, 6, c,fig.2\2.) of vary- 

 ing lengths and directions : sometimes only by 

 a deeper cell than ordinary. M. Bourgery 

 saw in this arrangement only a " labyrinth of 

 canals " (cananx ramifies bronchiques. ) Home 

 and Bauer, mistaking the intercellular passages 

 for the bronchi, remark, " the cells of the 

 human lungs are not dilatations of the bron- 

 chial tubes, but are regular cells in which the 



