116 



ABNORMAL ANATOMY OF THE LARYNX. 



tained the name of the false or adventitious 

 membrane of croup. This substance is of a 

 pale yellow colour, viscid and tenacious ; more 

 generally found in the larynx than the trachea ; 

 seldom occupying the entire circumference of 

 the tube ; unorganized ; incapable of becoming 

 the medium of union between opposing sur- 

 faces, and with a strong disposition to separate 

 from the surface on which it was originally 

 formed. It usually commences in the larynx, 

 and travels downwards along the trachea; more 

 rarely it seems to begin in the ramifications of 

 the bronchial cells; and again, still more sel- 

 dom is the entire of the mucous membrane 

 attacked at once, and the adventitious mem- 

 brane thrown out over its whole extent. Con- 

 sidered as a pathological production, this false 

 membrane of croup presents some curious and 

 interesting subjects for observation, for although 

 so generally met with that by some it has been 

 regarded as the essential characteristic of the 

 disease, yet perhaps it is not invariably or ne- 

 cessarily so ; at least I have seen cases so far 

 resembling croup in all their stages, that they 

 could not be distinguished from it during life, 

 in which dissection subsequently shewed the 

 mucous membrane swollen, and soft, and 

 pulpy, with copious submucous effusion, yet 

 without the formation of a single flake of 

 lymph. Possibly in the few cases of this de- 

 scription that came under my observation, the 

 disease had proceeded with a rapidity which 

 proved fatal before the membrane had time to 

 have been formed. Again, it is the only* 

 instance of lymph being produced on a mucous 

 surface as the result of active acute inflamma- 

 tion. In chronic affections membranous layers 

 of lymph are often formed, and in different 

 situations, as in the bronchial cells and the 

 mucous coat of the intestines, but the acute 

 produces it alone in the structures that are the 

 seat of croup. And lastly, it appears that this 

 effect of inflammation is restricted to patients 

 under twelve years of age. Mr. Ryland, in his 

 excellent treatise on the larynx, has published 

 a table from Bricheteau, by which it is shewn 

 from the experience of fourteen distinguished 

 authors, that croup " has never occurred at a 

 later age than twelve years, and very rarely at 

 that age." My friend, Dr. W. Stokes, con- 

 siders the cases published as examples of croup 

 occurring in the adult as not being inflamma- 

 tory croup at all, but analogous to the diphthe- 

 rite of Bretonneau, which will be shewn to be 

 a very different disease indeed. 



Such is the pathological condition of the 

 parts in the second stage of croup a condition 

 indicated by the increased difficulty of breath- 

 ing the pale and swollen countenance the 

 straining eye the dilated nostril and the purple 

 lip; by the occasional expectoration of some 

 portions of the false membrane ; and (as hap- 

 pens in every affection of the larynx) by severe 

 and protracted spasms of the glottis. If the 

 patient still continues unrelieved, the third and 



' For an apparent exception to this rule, see a 

 case published in the Dub. Journ. of Med. Science, 

 September 1838, No. 40, vol. 14. 



last stage supervenes. The child still breathes 

 with difficulty, but with increasing languor : 

 its countenance is pale; its lip bloodless; 

 there are generally convulsions, in one of 

 which the fatal event may take place ; or else 

 he sinks gradually, exhausted and worn out, 

 and dies comatose. And we are to look for 

 the actual and immediate cause of death not to 

 the larynx but to the lungs and brain. No 

 matter how much the membrane may be 

 swollen, or how extensively the false mem- 

 brane may have been formed, the rimais not 

 completely closed, and the patient dies, not 

 because there is an absolute insufficiency of air 

 to provide for the arterial ization of the blood, 

 but because some change has taken place in 

 the organ by which this most important func- 

 tion is performed. When the thorax is opened 

 the lung does not collapse under the influence 

 of atmospheric pressure : when the lung is cut 

 into, it is found to be loaded with dark blood 

 and with frothy serum, the effusion of which 

 latter is often so abundant as nearly to fill the 

 trachea. The brain, if examined, is found 

 congested, and not unfrequently is there an 

 effusion of serous fluid into its ventricles. 



The acute inflammation of the mucous mem- 

 brane of the larynx bears no resemblance in 

 the adult to that "in the child, excepting only in 

 the agonizing difficulty of respiration and the 

 fatality of the result, but the pathological con- 

 ditions are different, and therefore is the disease 

 in the adult far more manageable. I can 

 scarcely conceive, much less describe the ex- 

 istence of acute laryngitis to any dangerous 

 extent in the membrane alone without the 

 participation of the submucous tissue, in which 

 the perilous tumefaction is generally, if not al- 

 ways, seated ; I shall, therefore, as I have hi- 

 therto done, consider this affection in connec- 

 tion with its principal pathological result the 

 formation of an oedematous effusion. 



Mucous membranes in every situation seem 

 to be connected to the adjacent tissues by that 

 species of cellular membrane termed reticular, 

 as a provision that the courses of the canals of 

 which they form so important a part should not 

 be impeded by any accumulation of fat : and 

 this reticular membrane is more or less lax 

 according to the nature and consistence of the 

 subjacent structure. Where mucous mem- 

 brane is attached to bone, the nature of the 

 connecting medium is so short and close, that 

 in many instances it is scarcely observable, 

 and the membrane, in addition to its own func- 

 tions, appears to perform that of a periosteum, 

 whilst in other situations, as in the intestine, it 

 is so lax as to allow the organ to become dis- 

 tended to an almost unlimited extent. The 

 usual effect of inflammation on this reticular 

 tissue is an effusion of a serous fluid within its 

 cells, and the production of O3dema ; but this 

 is of little consequence where the tissue is 

 dense and close, and perhaps of still less 

 where the organ is widely distensible. The 

 larynx, however, presents an organ of a mixed 

 character the mucous membrane is here at- 

 tached to muscle and to ligament, and these 



