Vocal Cords in Quiet Respiration in Man, fyc. 423 



muscles just as the upper eyelid needs the support of its own" (The 

 italics are ray own.) 



So far Legallois. I have quoted him at length, first, because the 

 results of his experiments have, in the main, been corroborated by 

 practically every observer who has repeated his experiments ; and, 

 secondly, because it appeared to me most interesting that the same 

 thesis, the establishment of which is attempted in this paper, should 

 have been given out with almost prophetic foresight at the beginning 

 of the century by practically the first worker in this field. 



There is no need to quote at any length the experiences of subse- 

 quent experimenters, as they agree on all the main points with 

 Legallois' results, and as the whole literature of the subject has been 

 most carefully quoted and abstracted by Frey in the excellent prize 

 essay already mentioned. The general result of all these experi- 

 ments may fairly be thus summarised : that the effects of the sadden 

 redaction of the glottis to its cadaveric width vary very considerably, 

 first, with regard to the species ; secondly, with regard to the age of 

 the animal experimented upon ; thirdly, though in a less degree, with 

 regard to individual peculiarities of the animal. Whilst certain 

 species, such as cats and horses, not only in the first days after birth 

 but even when adult, are suffocated by the reduction of the glottis to 

 the cadaveric size, other species, notably dogs, suffer less and less in 

 proportion to their ages, so that, whilst they die when operated upon 

 a few days after birth, dyspnoaa only occurs on exertion when they 

 are operated upon when adult. Again other species, such as rabbits 

 and guinea-pigs, are not nearly so much inconvenienced as the species 

 so far mentioned, even when operated upon at a very early period of 

 their existence. 



Thus the general effect, in animals, of reduction of the glottis to 

 the cadaveric size during life is undoubtedly interference with 

 respiration, but the degree of interference immensely varies. 

 Obviously, under these circumstances, it is not permissible to draw 

 hard and fast conclusions from experiments on animals with regard 

 to the degree of interference which may be expected under similar 

 conditions in man, and the only reasonable conclusion which can be 

 drawn is that in all probability reduction of the human glottis to the 

 cadaveric position would also lead to some interference with normal 

 respiration, and more so in the young human subject than in the 

 adult. 



Even less satisfactory than experiments on animals are pathological 

 observations on man for the decision of the question whether reduc- 

 tion of the glottis to the cadaveric width interferes with normal 

 respiration. It is perfectly true that nearly all observers* who have 



For instance, v. Ziemssen, ' Handbuch der speciellen Pathologic,' vol. 4, pt. 1, 

 p. 456 ; Morell Mackenzie, loc. cit., p. 440 ; Gtottstein, loo. tit., p. 259, &c. 



