The standard writings of the English ana tomists issued at this period express chiefly the views of the continental authors above quoted. In Carpenter's Principles of Human Physiology, and Messrs. Todd and Bowman's Physiological Anatomy, excellent chapters will be found on the structure of the lungs. The works of the Wiirzburg Professor (Milker) contain the roost 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.
Rossignol. Luftzellen oder Lungenbldschen of the German writers). Looking down along a section throuigh 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 Minute Anatonzy of the Lobule.—The proper pulmonary tissue (b,fig.21 1.) begins where the bronchial tubes (a,fig. 21 1.),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 snzooth (a), like those of the bronchial tubes ; they become afterwards loculated (c) with cells or alveoli, like the terminal air-cells (e,b) (vesiculw s. celluke czerece s. Malpighiance, alveoli pulmonum • 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, fig.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, /lg. 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,b, e, fig.212.) 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 " (canaux ranziPs 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 tubes terminate." This really coincides with
the supposition of Reisseissen " trachem ramos ita per pulinones distribui, ut facta par titione multiplici, singuli quique ccecis nee ampliatis terminentur finibus, quibus vesiculm aeriferm constituantur." Moleschott has slightly modified the views of Reisseissen :— " Jam singulos ductus aeriferos, non uti they would accurately ansl.ver to the descrip tion of the " intercellular passages " fig. 210.; 'a' „fig. 212.). It is,therefore, obvious that two different minds, contemplating the same objects under two different preconceptions, would see in them " passages " or "infundibula." A lung injected with wax readily misleads to the error committed by Reisseissen of supposing each cell to be the separate termination of a separate bronchial branch. But it is certain Reisseissen voluit, ccecis nec ampliatis finibus terminari dicit, verum ad latera parietalibus vesiculis instructos esse testatur." Kiilliker adopts the views of Rossignol, and constructs an illustration which expresses more perfectly the views of the latter author.* If a series of hollow cells were disposed linearly, the points of contact being converted into foramina, as represented in this diagram, * " Mit denselben steben dann die letzen Ele mente der Luftwege, die Luftzellen oder Lungen 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 con tinuationes ita constructas causis supra dictis commotus ap pellaverim petiolos, atque hanc denomination em novam commend°, fines autem eorum =Thu catos nomine jam antea ipsis indito infundibula voco ; eos denique alveolos, qui in petiolis reperiuntur alveolos parietales, omnes vero, qui in infundibulis occurrunt, alveolos termi nales nomino."* Professors Schrbder Van der Kolk, Harting, Promotor,and their pupil Adrius Adriani, adopt the opinions of Rossignbl 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 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, intercellular passages, and air-cells will be readily understood.