436 VIVISECTION. 



only collateral here, I believe the proposition could be borne 

 out, that in by far the majority of instances the unreasoned 

 intuitive likings and dislikings, which impress us whether w T e 

 will or no, are in the end confirmed by reasoning. 



Assuming as granted that vivisection could never be pro- 

 secuted over so large a field as mortuary dissection, then one 

 great disadvantage of it by comparison with mortuary dissec- 

 ton, regarded as a means of giving operative facility, will now 

 be made apparent. It fails, and must fail, in evolving the 

 law of averages as affecting abnormal conditions of organism. 

 An anatomist will at once perceive the scope and purport of 

 the last objection ; but to aid the general comprehension of 

 it, I will give an illustrative example with strictly practical 

 bearing. 



One of the surgeon's greatest solicitudes, if not the very 

 greatest, in the conducting of operations, is that of heeding 

 the arteries. It happens that Nature is somewhat irregular 

 in her scheme of arterial distribution. Looking at the gene- 

 ral aspect of arterial supply, the impression likely to be cre- 

 ated is, that Nature has considered it a matter of secondary 

 moment how any part or parts of any organism or organisms 

 be supplied with blood, so that supply there be. Neverthe- 

 less there exists in all animals provided with a blood-circula- 

 tion such a preponderance towards one general arrangement, 

 that the anatomist is under no difficulty to establish a type ; 

 speaking of all deviations from that type as irregularities. 



In respect to arterial irregularities, it is a matter of the 

 highest as well as most commonly recognised value amongst 

 surgical operators, that the comparative importance of each 

 leading deviation from the normal type of distribution should 

 be appreciated, and impressed upon the mind statistically ; in 

 other words, from the consideration of average probabilities. 

 Assuredly no argument is needed to make good the propo- 

 sition, that directly proportionate to the field upon which the 

 observations are conducted, so will be the approximation to 



