Arterial Anomalies 5 
SVE AON Oh PNR DRS 
Arterial variations early attracted the attention of anatomists 
and were recorded as deviations from normal; they soon inter- 
ested surgeons and it is from this standpoint that Quain (1844) 
presented his great work; even as late as 1878 Hyrtl considered 
them principally for their surgical significance. Anatomists who 
studied the lower animals, as Cuvier (1838), recognized the simi- 
larity between some of these anomalies and the normal condition 
in animals and in recording the variations regularly spoke of the 
animals in which a similar condition obtains. The growth of the 
conception that a connection existed between the two, I will speak 
of particularly in the next section. 
Baader (1866) classified a large number of the mammalian 
conditions as analogous to variations in man. He did not make 
use of the facts then known concerning development and did not 
speak of a similarity indicating atavism. His idea of the way in 
which variations occurred was new; it was in effect that the 
earliest vessels are arranged as a net and that the great trunks 
develop through the enlargement of some of these channels while 
others degenerate. In keeping with this theory his conception 
seems to have been that the number of possible variations was 
limitless. Aeby (1871) held the same idea and Krause (1868) 
made use of a hypothetical plexus in some of his explanations. 
The conception of an arterial net was purely theoretic with its 
author but it has since furnished the subject for a controversy 
which need not be reviewed here. 
Ruge (1884) showed that variations fall into certain classes, 
1. €., are not innumerable, and he considered that a part at least 
of these variations have an atavistic meaning. The work of 
Hochstetter, Goeppert, Evans, Lewis and others has contributed 
much to the general subject of arterial variation but the intimate 
relation of their work to the subject of this study will permit a 
detailed review of their researches at proper points in the subse- 
quent pages. 
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