the natural Distribution of Insects and Fungi. 61 
matter, Articulata or Ptilota, 1s a circle, must be obvious to every 
observer; and consequently they do not fall within the sphere of 
M. Fries's definition already given of a natural group, but each 
of them form two circles, which therefore, according to our 
author, are natural groups. We might turn even to the well- 
known great division of the vegetable kingdom into phænoga- 
mous or cotyledonous and cryptogamous or acotyledonous plants, 
where the former are clearly the centrum, and divisible into 
two natural groups; but surely enough has been said to show, 
that the notion of M. Fries on this head is in every respect, but 
the mode of expressing it, the same identically with mine. 
When he states the determinate number to be four, and we in- 
vestigate the signification attached by him to this proposition, we 
discover that it is in effect five. How M. Fries was led to the 
number four, we have already endeavoured to explain; and it is 
truly worthy of observation, as an almost conclusive argument 
for the determinate number being five, that M. Fries himself is 
at last obliged to adopt it. This open abandonment of his theo- 
retical number four, which we have seen that he had virtually © 
abandoned before, takes place moreover in that part of his work 
which, relating to the more minute groups, is therefore most in- 
dependent of theory, and most subjected to the keenness of prac- 
tical observers. Here, in brief, he finds himself tied down to 
stubborn facts, and it is rather interesting to mark the result. 
The only genera of Hymenomycetes Pileati which he discovers to 
be divisible are, Agaricus, Cantharellus, Thelephora, Hydnum, 
Boletus, Polyporus and Dedalea, some of which, as Agaricus, are, 
as he says, of the first dignity ; others, as Cantharellus, of the 
second*. Now every one of these genera, or at least their typi- 
cal groups, aré divided by M. Fries himself into five, with the 
* 'The groups here said to be of the second dignity, appear to be of the same degree 
with the genera Phaneus and Scarabaus of the Hore Entomolocica. | 
single 
