Bauhaus-Universität Weimar

CONTRACTIONS OP THE TRACHEA.AND BRONCHI. 
319 
divided. Such movements have been attributed to shocks commu¬ 
nicated from the thoracic parietes; they might also arise from con¬ 
tractions of the heart or of the pulmonary veins. Haller never saw 
these motions of the lungs; in his experiments the lungs always col¬ 
lapsed perfectly when the thorax was completely opened: the result 
of my experience is the same, and I conjecture that Flormann and 
Rudolphi must have been deceived. The farther consideration of 
this controversy is merely of historical interest; arguments and coun¬ 
ter-arguments are repeatedly brought forward, and the inquirer is at 
last left to the testimony of his own eyes, which in my case is op¬ 
posed to the hypothesis. Motions were observed by Tiedemann in 
the respiratory organ of the Holothuria. Treviranus relates that he 
has seen motion excited in the lungs of the frog by the application 
of tincture of opium and extract of belladonna. I do not know 
whether the celebrated author of the “Biologie” attributes much 
importance to this observation. Frogs fill their lungs with air from 
their throat, and the air escapes on the glottis and nostrils being 
opened. If the glottis is opened, the lungs become permanently col¬ 
lapsed, and no contractions can be excited in them. (Consult, on this 
subject, Lund, Vivisectio?ien, pp. 240—243.) 
The contractile power of the trachea and its branches is, however, 
less equivocal. It might be supposed that the bronchi contributed 
to produce the motions observed by Houstoun, Bremond, Flormann, 
and Rudolphi. It is, however, still matter of doubt whether the 
muscular fibres of the trachea produce any rhythmic motions of 
contraction and dilatation. The transverse muscular fibres on the 
posterior surface of the trachea are well known. Muscular fibres 
are also described as existing on the smaller bronchi. Reisseissen 
(De fabrica Pulmon. Berol. 1822, fol.) has contributed most to 
draw attention to these fibres. He says that by means of a lens he 
has recognised muscular fibres on bronchi so small that their cartila¬ 
ginous plates could no longer be seen. 
It is remarkable that there exists at present no direct proof of the 
contractility of the muscular fibres of the trachea and its branches. 
All the ducts of glands possess true muscular contractility; they have 
the power of involuntary motion. (See section on Secretion.) But 
contractions of the fibres of the trachea have hitherto been observed 
only by Krimer. ( Untersuchungen über die nächste Ursache des 
Hustens. Leipz. 1819.) Wedemeyer applied mechanical stimuli 
and galvanism to the whole circumference of the trachea in a dog 
and a hedge-h©g, both with and without previous division of the 
mucous membrane, but could perceive no contractions produced; 
while bronchi of three-fourths of a line to a line in diameter con¬ 
tracted gradually until their cavity was nearly obliterated. Wede¬ 
meyer laid bare the trachea in a living dog, and freed it from cellular 
tissue for the space of two inches; he then cut out a portion in front, 
and irritated the posterior wall of the trachea mechanically and by 
galvanism, but could not produce the slightest contraction. Wede¬ 
meyer now opened the thorax quickly, and removed the lungs with 
their bronchi. He made several sections of the larger bronchi, but
        

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