the natural Distribution of Insects and Fungi. 59 
tas imperfectionem potius indicat; perfectissima enim sunt in 
quávis sectione ab omnibus aliis remotissima. Sic perfectissima 
animalia et vegetabilia, que maxime a se invicem remota ; infi- 
ma, quorum limites confluunt." Hence it follows, that the cen- 
trum, or perfection of a group, is in fact that part of the circum- 
ference of the circle of affinity which is farthest from the neigh- 
bouring group, and exactly the same thing with what in the Hore 
Entomologice has perhaps more happily been called Type. 
Indeed the confusion arising from the use of the word centrum, 
as applied to a point in the circumference of a circle, is still in- 
creased by applying the word radii to those groups likewise in the 
circumference which lead from one centrum or type to another, 
and which I have termed annectent groups*. The use of these 
terms centrum and radii is the more unfortunate, as our author 
never for a moment takes them in any other sense than that in 
which I have used the expressions type and annectent groups. 
When, therefore, he says that in every group, whether class, 
order, &c. there are a centrum and radii, we must understand him 
as meaning, that there are in every circle first a type or normal 
form expressing the perfection of the superior group to which it - 
belongs; and secondly, annectent groups connecting this type 
with other groups. Or, to take his own words, “ In centrum quod 
dom, which I have given in Hore Entomologicæ, p.205, I may add the botanical 
authority of Professor Schweigger. “ Nec etiam genera et ordines plantarum in li- 
neam a cryptogamicis ad dicotyledoneas progredientem ita disponi possunt, ut familia 
quivis præcedentis structuram magis evolutam praebeat. Vix ullus de vegetabilium 
serie usitata, a cotyledonum numero deducta, affirmat, plantas dicotyledoneas omni 
ratione monocotyledoneis esse anteponendas." p. 6. De Plantarum classificatione 
naturali Disquisitionibus Anatomicis et Physiologicis stabilienda Commentatio, Auc- 
tore A. F. Schweigger, &c. Regiomonti 1820. 
* There are several other terms used by M. Fries to designate his groups, and which 
differ from those employed by me to express the nature of similar groups. Thus, his 
intermediate genera are my osculant genera ; his subordinate genera are my types of 
form or sub-genera, &c. ; 
12 species 
