556 
A. O. ZWICK. 
their frequency, and others from the fact that they exist in situ¬ 
ations where they are liable to affect the progress or results of 
surgical operations. 
Many vascular variations repeat forms which are natural in 
different species among the lower animals, representing a hark¬ 
ing-back in some cases to forms that have perished; others are 
obviously due to the persistence of early fetal forms of distribu¬ 
tion and not a few are explicable on the supposition of abnormal 
enlargement or diminution of caliber of naturally existing ves¬ 
sels. Again, the dimensions of the arteries vary to some extent 
in different individuals, in the two sexes, and at different periods 
of life. Now, may some of these variations from the so-called 
normal not also represent lesser degrees of efficiency in the vas¬ 
cular system of the individual, SO' shall I not say, afflicted ? 
My idea is that tuberculosis depends perhaps much more than 
commonly thought upon anatomical predisposition to infections. 
How often do we observe that a family history indicates a marked 
predisposition to tuberculosis? Of course, this predisposition 
“ resides in the tissues,” but are we entirely sure that it resides in 
their quality, in their physico-chemical, biological characters, in a 
species of degeneration, vitiation, depravity of their vital char¬ 
acteristics, as the argument usually runs? I am of the opinion 
that such predisposition, or I would rather say, predetermination, 
resides to at least an equal, perhaps a preponderating, dominant 
degree and extent in their anatomical arrangement. 
Now, this idea is not new. Confer the views of Hippocrates, 
the father of medicine, on this very point: the winged or alar 
type of chest, characterized by the everted, winglike scapulae pro¬ 
jecting from a flat, narrow thorax, was described by him four 
hundred years before Christ, twenty-three centuries ago, as pre¬ 
disposing to affections of the lungs; the typical alar, phthisical 
thorax! Consider: the usual seat of the primary lung lesion is 
one of the apices, usually the right After one apex has been 
attacked the disease usually extends first to the apex of the lower 
right lobe (or, at any rate, that of the same side that has first 
been attacked in the upper apex), and then to the other. Would 
