66 Mr. AV. S. Macleay on the Structure of the Tarsus 



with their notions of afhnity ; the consequence being, that al- 

 though proposed as a natural system, they proved it to be arti- 

 ficial ;— as, for instance, in the case of the genus Heterocerus, 

 which is acknowledged by them to be tetramerous*, and is never- 

 theless placed among the F entamera. It was therefore with some 

 shadow of reason that other entomologists, who regarded all simi- 

 lar systems only as they were convenient dictionaries, complained 

 at being called upon to see more than really existed in nature, 

 and to account such an insect to be pentamerous merely because 

 the French system would have it so. 



The leading objections, however, which I have made to this 

 system in the Borœ Entomologicœ are, in the first place, that it 

 fails de facto in its object of superseding the Linnean and Fa- 

 brician systems ; inasmuch as, instead of giving us a natural 

 series, it has only added to the number of artificial systems 

 already invented ; and secondly, that it fails de jure ; that, in 

 brief, it could not have done otherwise than fail, inasmuch as 

 it has, like most other principles of arrangement, been erro- 

 neously applied to divide Cu/coptera, when the grand recpiisite 

 must always be the natural method of uniting them. It is indeed, 

 as I have elsewhere attempted to showt, a great error to confound 

 the Creator's distribution of his works with our own method of 

 dividing a subject into heads for the sake of perspicuity. That 

 system, in short, which depends on the division of organs or pro- 

 perties must necessarily be artificial, while that which depends 

 on their 'method of variation must be the natural one. 



But 1 have now to propose a third objection to the tarsal 

 system ; an objection which will, I suspect, not a little sur- 

 prise those entomologists who have been in the habit of adopt- 

 ino; it as a convenient mode of arranoino; the contents of their 

 cabinets. It is, that the very basis of this system is erroneous, 



* Gen. Lisectvnuii, vol. ii. p. b'Z. f llortc Eiiluinulogictc, p. 4 J4. 



since 



