66 Mr. W. S. MacrzEav on the Structure of the Tarsus 
with their notions of affinity ; 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 Pentamera. 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 Hore Entomologice 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 Coleoptera, when the grand requisite 
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 I 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- 
ing it as a convenient mode of arranging the contents of their 
cabinets. It is, that the very basis of this system is erroneous, 
* Gen. Insectorum, vol. ii. p. 52. + Hore Entomologice, p. 454. 
since 
