the natural Distribution of Insects and Fungi. 57 
be shown, that in the animal kingdom the same law is followed 
by nature ; in short, to take an instance, if it could be proved 
that the Annulosa may either be divided into four groups, viz. 
Ametabola, Crustacea, Arachnida and Ptilota, where this last is 
remarkably capacious and divisible into two natural groups, viz. 
Mandibulata and Haustellata, or that annulose animals may be 
divided at once into five groups of the same degree, but of which 
two have a greater affinity to each other than they have to the 
other three—if, I repeat, this could be proved, should we not 
be justified in affirming that the rule, so far as concerns Insects 
and Fungi, is one and the same? The possibility of thus distri- 
buting the annulose animals has, however, been demonstrated 
already in the Hore Entomologice ; and it is the way in which we 
ought to take the rule that only now remains to be investigated. 
In short, since only two methods* have yet been found to coin- 
cide with facts as presented by nature, the question is, whether we 
ought to account Fungi as divisible into five groups, or into four 
of which one forms two of equal degree. Now I think it may 
without difficulty be shown, from our author’s own observations 
and rules, that there is only one determinate number which regu- 
lates the distribution of Fungi, and that five is this number. 
* The number seven might also perhaps, for obvious reasons, occur to the mind, 
were it allowable in natural history to ground any reasoning except upon facts of or- 
ganization. The idea of this number is however immediately laid aside, on endeavour- 
ing to discover seven primary divisions of equal degree in the animal kingdom. It is 
easy, indeed, to imagine the prevalence of a number; the difficulty is to prove it. The 
naturalist, therefore, requires something more than the statement of a number, before 
he allows either a preconceived opinion or any analogy not founded on organic struc- 
ture to have an influence on his favourite science. He requires its application to nature 
and its illustration by facts. As yet, however, no numbers have been shown to prevail 
in natural groups but five, or, which is the same thing, four of which one group is di- 
visible into two. Perhaps, indeed, the most clear method of expressing ourselves on this 
subject is to say that, laying aside osculant groups, every natural group is divisible into 
five, which always admit of a binary distribution, that is, into two and three. 
MOL. XIV. I In 
* 
