the natural Distribution of Insects and Fu7igi. 6l 



matter, Articulata or Ptilota, is 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 phaenoga- 

 mous or cotyledonous and cryptogaraous 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, Hyd7ium, 

 Boletus, Polyporus and Dcedalea, 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, are 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 Pharueiis and Scarabaus of the Hora Entomologies:. 



single 



