The bronchi and pulmonary blood-vessels : their anatomy and nomenclature, with a criticism of Professor Aeby's view on the bronchial tree of mammalia and of man / by William Ewart.

  • William Ewart
Date:
1889
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Licence: Public Domain Mark

Credit: The bronchi and pulmonary blood-vessels : their anatomy and nomenclature, with a criticism of Professor Aeby's view on the bronchial tree of mammalia and of man / by William Ewart. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    belief iu tllB epartei'ial theory. If iuappli- Ciible to man, the theory is self-coii- demuod iu niammalia in ceueral. Generaliza- tion was probably iipplied pre- maturely to iusutti- cicut facts. Complete criticism later. Doubt as to the compe- tence of the pulmonary artery as a test for the bronchi. If prece- dence de- termined 1)}' bulk,bronchi and air cells would rank first. A ssuniing equality between may bo known in these pages as the eparterial theory. Founded upon anatomical research it is considered hj its author to be unassailable; and hitherto the event has fully justified that belief. The diffidence with which I approach its discussion is not due to my entertaining a belief of the same nature, or even any doubts; but rather to respect for the authority which belongs to any views coming from so distinguished a source; and especially for the great value of the woi'k in which they are conveyed. Any criticisms now ventured against the eparterial theory are pri- marily directed against its applicability to the genus Homo. In connection with comparative anatomy my opinions can claim only a secondary value. Nevertheless should evidence arise showing the absolute inaioplicability of tlie e]Darterial theory in man, its applicability to the mammalian series must become exposed to serious doubt. Professor Aeby's whole endeavour has been to unify the bronchial peculiarities of the mammalian genera under one comprehensive scheme. If in the more limited district of human anatomy the theory should prove to be untenable, it is but logical that the arguments by which he has sought to establish the general fitness of his doctrine should complete its refutation in the field of comparative anatomy. Professor Aeby's Facts Correct, but Incomplete.—The facts advanced by Professor Aeby in connection with the eparterial theory are obviously correct: we can only object to his having given us so few. Nay, it was a misfortune that the analytical study of the bronchial system, which he has initiated, should not liave been pushed further by him before the generalizing methods of comparative anatomy were brought into play. Facts though correct may be incomplete; and doctrines built upon them in their immature stage may lapse into the rank of theories when further facts give room for larger constructions. The anatomical facts hereafter to be described possess this completing value. Their conflict is with the theory not with Professor Aeby's laborious conquests in the field of anatomy. The Principle of the Theory questioned.—Although the adequate criticism of the eparterial theory must of necessity be postponed to the section of this work dealing with anatomical detail, it is possible even at this stage briefly to examine the principle which underlies it. A cjuestion at once arises as to the conq^etence of the standard used as a test for the ntorphological value of the bronchial tubes. Are we sufficiently justified in using the position of the pulmonary artery as a qualitative test ? Is it seniority in development, or is it greater physiological importance, which is considered to raise the pulmonary artery so far above pulmonary structures, and to render it standard-giving ? Were precedence regulated according to bulk, the bronchial tree, taken together with its parenchymatous extension, would be found in mammalia greatly to exceed in cubic space the vascular, and therefore to be more entitled to the first place among all pulmonary structures. Alternative Terminology proposed.—That the lung is pre-emi- nently an air-organ wc may perhaps not venture to assert, for throughout the
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