PARASITIC DISEASE OF THE LUNGS. 801 



as well as Professor Gamgee, oppose this view. Mr. Dicldnson 

 says — " The idea entertained of a direct passage of these to the 

 lungs appears to me paradoxical and in nowise probable. Their 

 migration, I am inclined to believe, is a work of time; and 

 hence, as I have frequently observed, the parasites abound in the 

 alimentary canal in large numbers, give rise to aggravated symp- 

 toms which terminate fatally when no worms or their eggs are 

 to be detected by the naked eye, at least in the lungs or bronchi." 

 Professor Armatage informs me he has also observed this in 

 many instances. Mr, Armatage says — " The presence of Strongy- 

 lus filaria in the lungs of lambs and sheep, I think, cannot be 

 explained by any theory which describes — no matter with what 

 minute exactness and elaborate detail — the unnatural and, I 

 might add, almost impossible mode of their passing direct 

 through the windpipe to these organs. "We all know, as possess- 

 ing some slight knowledge of physiology, how a hair, a bread- 

 crumb, drop of water, &c., will irritate the glottis or entrance to 

 the windpipe, and give rise to the most painful and convulsive 

 coughing. These are, however, objects of an inanimate charac- 

 ter, and irritate by mere presence. How much greater, then, 

 would be the effects of a live worm or worms insinuating them- 

 selves on the delicate structures, and especially when the natural 

 barbs or booklets, as described by Professor Simonds, are put in 

 operation. The supposition, I think, suffers much under the 

 great probability that violent coughing taking place on the 

 entrance of a worm or worms would entirely expel them. If 

 they are expectorated in large numbers from the recesses of the 

 bronchial tubes, they will most assuredly be compelled to 

 evacuate much more rapidly at their entrance to the windpipe." 

 The same gentleman further says — " We must not overlook the 

 important fact that young lambs are principally affected. In 

 them the tissues are more easily pierced, and their passage from 

 the lung tissue to the bronchial tube readily effected. In older 

 animals they remain enveloped within a matrix of cretified sub- 

 stance and metamorphosed lung tissue, in order, as it were, to 

 guard against their effects. If their passage to the lungs were 

 always more direct, the opposite would be the case, and our old 

 animals would die as rapidly as the young ones." Professor 

 Gamgee says — "The migration from the mouth or alimentary 

 canal to the lungs certainly requires a more complete explana- 

 tion than has hitherto been given." 



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