60 Mr. W. S. MacnEAY on certain general Laws regulating 
species plurimas continet, character optime quadrat. Radii ad 
reliquas classes (scilicet ordines, genera, &c.) abeuntes, utrius- 
que classis characterem conciliant, sed ad illam (viz. the typical 
group) cujus character maxime eminet referuntur." 
If then the determinate number in which Fungi are naturally 
grouped be four, and if it thus appears that, according to M. Fries, 
every natural group is a circle, having in its circumference a 
point of perfection or typical group called a centrum, and annec- 
tent groups called radii, it is evident that there must be one cen- 
trum and three radii for every group. But observe what imme- 
diately follows as the result of M. Fries's observation: ‘Centrum 
abit semper in duas series, inferiorem et superiorem, quarum illa 
ad antecedentem hzc ad sequentem classem (l. radium) eviden- 
tius accedit." 
This rule being determined, M. Fries goes on moreover to say, 
that these two series which compose the centrum are always ana- 
logous at their corresponding points. Consequently, in every cir- 
cle he admits the existence of two central groups and three radial ; 
that is, in all, five natural groups. Now this truly is the case 
throughout the whole animal kingdom. Organized matter is the 
centrum of matter, and is composed of animals and vegetables. 
Articulata*, or animals possessing an articulated axis, form the 
centrum of the animal kingdom, and are composed of Vertebrata 
and Annulosa. The Ptilota of Aristotle, or winged insects, form 
the centrum of the Annulosa, and are divided into Mandibulata 
and Haustellata. And so on, we shall ever find a natural group 
to be a circle of five minor groups, and that two of these minor 
groups form what M. Fries would call a centrum, or, more cor- 
rectly, have some character in common which distinguishes them 
from the other three. That neither of these groups, viz. organized 
* This name ‘has been applied to the Annulosa, as characterizing them alone, but 
improperly, inasmuch as the vertebrated animals are articulated. 
matter, 
