172 REPORT — 1844. 



careful inductions and the most unprejudiced reasonings of subsequent na- 

 turalists have shown to have no claim to our adoption as a general law. 

 Without entering further upon the vexata qucestio of the " Quinary System" 

 than as regards its application to ornithology, I may remark that if we can 

 show that this supposed universal principle fails in its application to any one 

 department of the animal kingdom, it loses its character of universality, and 

 a presumption is raised against its truth even as a special or local law. The 

 quinary system in fact includes several distinct propositions, the truth of any 

 one of which does not imply that of the remainder. First, it is laid down that 

 all natural groups, if placed in the order of their affinities, assume a circular 

 figure ; secondly, that these circles are each subdivided into^t^e smaller circles ; 

 thirdly, that two of these are vormal, and the remaining three aberrant; and 

 fourthly, that the members of any one circle represent analogically the cor- 

 responding members of all other circles. I shall have occasion to recur to 

 these points in speaking of Mr. Swainson's writings, and at present will merely 

 remark, that the application by iMr. Vigors of these novel and singular doc- 

 trines to the class of birds contributed in no small degree to the advancement 

 of ornithological science ; for however erroneous a theory may be, yet the 

 researches which are entered upon with a view to its support or refutation 

 invariably advance the cause of truth. Alchemy was the parent of chemistry, 

 astrology of astronomy, and quinarianism has at least been one of the foster- 

 parents of philosophical zoology. Another debt of gratitude which we owe 

 to the quinarians is the broad and marked distinction which they were the 

 first to draw between Affinity and Analogy — between agreements in 

 essence, and agreements in function only and not in essence, the one consti- 

 tuting a natural, and the other an artificial system. And although their 

 foregone conclusions sometimes led them to mistake the one for the other, 

 yet by their clear definitions on the subject they enabled others to detect the 

 errors which in such cases they could not see themselves*. 



In 1824 Vieillot presented a new edition of his system, with but slight 

 alterations, in his ' Galerie des Oiseaux,' and in the following year Latreille 

 proposed another arrangement, which however diff'ers very little from that of 

 Cuvier as finally left by him in the second edition of his ' Regne Animal,' 

 1829. The celebrity of its author caused the latter work to be speedily 



* The distinction between affinity and analog)' is as yet but imperfectly established on the 

 continent, or at least the terminology employed is very vague. French Avriters continually 

 use the term analogie to express wliat we call affinity, a defect in their scientific language 

 which they might easily remedy by making use of the word " affinite," and by restricting 

 analogie to its true meaning. The same inaccuracy also exists in the language of geologists, 

 British as well as foreign, when they speak of the recent, analogue oi dLio?,&\\, meaning thereby 

 that recent species which has the strongest affinity to the extinct one. They might term it 

 with more propriety the recent affine. A similar alteration would also introduce greater pre- 

 cision into the terminology of comparative anatomy. The parts which in different groups 

 of animals are essentially equivalent, though often differing in function, are commonly termed 

 analogous members, but it would be more correct to call them affine members, and to restrict 

 the term analogous to those organs which resemble in function without being essentially equi- 

 valent. Thus the tooth of Monodon, the nose-horn of Rhinoceros, the intermaxillaries of 

 Xiphias, and even the rostrum of a Roman galley, all perform a similar function, and are 

 therefore analogous organs, but the relation between the weapon of offence in Monodon and 

 the masticatory teeth of other Mammalia is an agreement in essence but not in function, and 

 is therefore not an analogy but a real affinity. There is yet a third kind of relation between 

 organic beings which does not deserve the name of analogy, but which may be simply called 

 resemblance, consisting of a mere correspondence in form, but not in function or essence, 

 such as tlie resemblance between Murex haustellum and a Woodcock's head, between Ophrys 

 apifera and a Dec, &c., a relation which is in every sense accidental, though the advocates 

 of the quinar)' theory have often regarded it as a true analogy. 



