22 Mr. W. S. Macleay on the Comparative Anatomy 



Birds, and the point of nearest approach made by Birds to 

 Mammalia. 



In the discussion of these subjects I must not be expected to 

 produce any original facts. This, indeed, would not answer my 

 purpose ; since, in all similar questions, the instrument which is 

 at once safest for the wielder, and most forcible against those for 

 whom it is intended, is the argumentum ad verecundiam. 



First, as to the orders of Mamynalia : — there is one to which we 

 must all look with peculiar interest, as being that of which Man 

 forms the type. Great as is the gulf between Man and the 

 Ourang Outang, between the Bimana and Quadrumana of Cu- 

 vier, it is impossible not to see, with Linnaeus, that they possess 

 many characters in common*, and consequently impossible not 

 to agree with him, that they form one group, which may be 

 distinguished from all others by the general structure of their 



first by not carefully investigating the value of the analogies on record, and then by 

 trusting to the theory of parallelism in preference to the less fallible guide of affinity, he 

 has produced a series, which, in the conclusion, he himself discovers not to be valid. 

 Whether the affinities of his minor groups be of superior value he does not enable us 

 to judge, as no reasons whatever are given for them. This mode of proceeding is 

 the more to be regretted, from his evidently being conversant with the various forms 

 of Mammalia, and from his having pointed out the orders in a very lucid manner; 

 from which I have not failed to derive advantage. This much, I fear, cannot be said 

 of the contents or affinities of these orders ; and therefore, as he has done me the honour 

 of referring to my views of the subject (and his paper, indeed, purports to be a quinary 

 distribution of the class), I may, perhaps, be allowed to express a hope that the ques- 

 tion may be followed up. One thing is sure, that nothing can be easier than to make 

 five groups, provided we do not conceive it necessary to prove them to be natural. 

 Having, therefore, stated his propositions, he will be expected to prove them either by 

 original observations of his own, or the recorded ones of others. At present his paper 

 proves nothing, ascertains nothing ; but leaves every affinity to be pointed out. I need 

 scarcely say, that without some such proofs in detail of the connection between the 

 component parts of the group, and thus of its unity, his propositions must remain 

 dubious, and all new names without authority. 

 * Amotn. Acad. vol. v. p. 67 el seq. 



skull. 



