42 The Botanical Gazette. [February, 
tion must be made of the genus Salix ‘which has developed 
means of insect attraction). Of these the Salicaceze are 
known to be old, for the oldest fossi! dicotyledons are of the 
genera Salix and Populus. None of them include many gen- 
era, and this again is a common attribute of old orders and 
a sign of approaching extinction, according to Darwin’s rule» 
that the dominant orders are those of numerous genera and 
species. 
Piperacee include 8 genera and 1000 species. 
6 ve 6 “e 
Platanacee  ‘' I 
Up auddcees eR et hot 20RecS 
Myricace solic OE aie seh eer ahexorts 
Cupar So 10 (ou hon ZOO. et 
Wa CaCede on ASS SE AO BO st A 
The genera are conspicuously few. The Piperacee alone 
have a large number of species and of their method of fertiliza- 
tion Iam not sure. The group Saururee, represented in our 
flora, is apparently adapted to wind“fertilization. Moreover 
many members of the Chenopodiacew, Amarantacee, Poly- 
gonacex, Urticacee and some Empetracee are anemophilous. 
All this is in marked contrast to the state of things among 
the younger and more highly developed exogens. For of the 
50 polypetalous orders one is partly wind, partly water-fer- 
tilized ; of the 33 gamopetalous orders, only one is largely 
anemophilous, and of that one, the Plantaginea, .the typical 
genus is considered by some authorities to be degraded. 
Here, too, the question of color comes to our aid. In 
Accordingly we 
dull shades pre 
‘American Naturalist, Sept. 4, 1890. 
