25 
and has besides introduced quite a number of indepen- 
dent alterations in the classification, which at any rate 
in part must be regarded as improvements. TOURNE- 
FORT'S system has 22, ARTEDI'S 25 classes. These classes 
are resolved into orders or sections. As a basis of 
subdivision are principally employed characters present 
in the appearance and nature of the flower and the 
fruit, but also in the relative positions of these, one to 
another. TOURNEFORT paid considerable attention to the 
two first-named groups of properties; that ARTEDI, on 
the other hand, perceived the value of the third, is a 
great point to his credit, as it was not until far later 
that its actually great importance in a systematic re- 
gard was recognised and insisted upon by botanists 
generally. Of the definite improvements in ARTEDI'S 
classification, as compared with his predecessor's, some 
few may be pointed out here. Coniferous trees and the 
birch-alder group were not differentiated by TOURNEFORT; 
ARTEDI classifies them in two sections. The bird-cherry 
is recognised by ARTEDI as possessing stone-fruit, and 
is marked off in a separate section from bilberries, red 
whortleberries and their congeners; TOURNEFORT, on the 
other hand, places not only all these but also the elder- 
tree, the honeysuckle and others in one and the same 
section. The division in ARTEDI'S work embracing Ribes, 
Berberis and Rhamnus is of course heterogeneous, yet he 
has at all events relegated Rubus to another place, which 
along with some others was classified by TOURNEFORT in 
the same section as the above. Practically all the crypto- 
gams are treated by TOURNEFORT as constituting one class 
of two sections, one of which, however, is also made to 
include not only algae but corals, bryozoa, spongiae and 
many other lower-type marine animals. ARTEDI, again, 
accords two classes to the cryptogams, containing six 
sections, viz. 1) algae; 2) lichens and mosses; 3) per- 
manent tree-fungi (amadou), which appeared to him to 
differ essentially from: 4) the perishable earth-fungi; 5) 
typical ferns; and, finally, 6) the Osmunda and hair-moss. 
Horsetail and nettles, according to ARTEDI, are far apart 
