268 



RESPIRATION, ORGANS OF. 



that Reisseissen mistook the infundibula of 

 Rossignol which are loculated with the ulti- 

 mate cells, both terminally and laterally, for 

 the separate ends of separate bronchial tubes. 

 It is no less certain that Rossignol has disposed 

 with unnatural precision the "cells" and 

 "passages" of which the lobule is composed. 

 Schultz, again, has erred in viewing the in- 

 tercellular passages in the light of " bronchial 

 petioles:" Bronchiolorum continuationes ita 

 constructas causis supra dictis commotus ap- 

 pellaverim petiolos, atque hanc denominationem 

 novam commendo, fines autem eorum amplifi- 

 catos nomine jam antea ipsis indito infundibula 

 voco ; cos denique alveolos, qui in petiolis 

 reperinntur alveolos parietales, omnes vero, 

 qui in infundibulis occurrunt, alveolos termi- 

 nales nomino." * 



Professors Schroder Van clerKolk,Harting, 

 Promoter, and their pupil Adrius Adrian!, adopt 

 the opinions of Rossignol in relation to the 

 disposition of the air-cells and passages within 

 the lobuli. Whether the intercellular passages 

 be distinguished by that name or by that of 

 the infundibula, it is certain that they differ 

 both from bronchial tubes and from the ulti- 

 mate air-cells by a greater diameter. The 

 nearer they are to the point of their attach- 

 ment to the bronchial tubes, the more tubular 

 or cylindrical their figure or outline ; the fur- 

 ther, the more irregular and inosculating, until 



Fig. 216. 



A. section at rii/ht angle to the a.res of the " Infun- 

 dibula" showing the alveoli (b, c). (After Rossignol.) 



finally they terminate in air-cells ; not after 

 the manner supposed by Reisseissen in form of 

 a Florence flask ; for the extreme cell has the 

 same diameter as the tube itself. From the 

 accompanying diagram, constructed by the 

 author, the relation between the bronchi, 



* Disq. cle Struc. et Text. Canal, aurif. Scripsit 

 Ernest Schultz, Lypsiaj, 1S50, p. 34. 



intercellular passages, and air-cells will be 

 readily understood. 



It is, then, important to remember that the 

 intercellular passages are open spaces between 

 the ultimate cells, their walls being constituted 

 of these latter. Like the ultimate cells, there- 

 fore, they participate actively in the process of 

 respiration. They are not merely convective 

 conduits. Since they proceed at every plane 

 and angle from the centre of the lobule, a 

 section of the latter in any direction will cut 

 these passages both transversely and longi- 

 tudinally. 



Ultimate Air-Cells of the Lungs. Vesiculce, 

 s. cellulce derece, s. Malpigkiarue, alveoli put- 

 monum ; Rossignol. An air-cell in the human 

 and mammalian lung is a space circumscribed 

 by a single wall of reticulated capillaries, and 

 varying infinitely in figure, and presenting in 

 different parts of the lung numerous varieties 

 of size ; each cell having an opening embracing 

 a section, more or less considerable, of its 

 circumference. The cells on the walls of the 

 intercellular passages, (the sides of the in- 

 fundibulum of Rossignol) may be defined 

 as mere cup-shaped depressions, sometimes 

 perforated at the bottom by a large foramen 

 opening into one or more cells. Under the 

 pleura the air-cell occurs as a four or six-sided 

 chamber, of which the bottom, presenting under 

 the pleural membrane, is rounded, and might 

 readily be mistaken for the fundus of a pear- 

 shaped vesicle, the apex running into a bronchial 

 tubule. If a cell, situated in the central parts 

 of a lobule, be selected for examination, it will 

 be found as a polyhedral alveolus, one or two 

 or more of whose sides are deficient or con- 

 verted into a foramina, through which its 

 enclosed space communicates with those of 

 contiguous cells. No cell is a perfect geome- 

 trical figure such, that is, as would be formed 

 by regular plane sides ; because ridges and 

 partial partitions, from the encroachment of 

 the angles of neighbouring cells, project into 

 and multiply its interior. It is not often that 

 the eye falls upon a unilocular cell having only 

 one opening : they occur most frequently as ir- 

 regular, angular spaces, with one or more im- 

 perfect sides, fig. 219. Those cells which com- 

 municate directly with the bronchial tubes and 

 intercellular passages open into them by large 

 circular apertures ; and they are themselves 

 similarly perforated, to communicate with other 

 vesicles, which again open into others beyond 

 them ; so that each of the openings in the air- 

 passage leads to a series of cells, "extending 

 from it to the surface of the lobule. The 

 vesicles which communicate directly with 

 the air-passages are more minute, and have 

 a closer vascular network than those which 

 lie nearer to the surface of the lobule; an 

 arrangement which is in beautiful harmony 

 with the relative facility by which the air 

 in them respectively is renovated. The dia- 

 meter of the human air-cells is about twenty 

 times greater than that of the capillaries 

 which are distributed upon their parietes, 

 varying, according to the measurement of 



