300 
high northern varieties are enduring; only a few of them fail annu- 
ally to set their fruit and ripen their seed. An annual plant disap- 
pears when for a single season it fails to ripen its seed. 
A comparison of the flora of Spitzbergen and the high portions of 
the Alps and Pyrenees shows that the former are the lost children of 
European flowers that have since the Glacial epoch survived at great 
altitudes in the mountains as well as in the damp, cold morasses of 
central Europe. 
A comparison of the flora of Taimyr and the mountains of southern 
Siberia shows that the northern flora has wandered thither and be- 
come acclimatized from the southern, and that this process is still 
golng on. 
CEREALS. 
The elaborate report of Brewer on cereals, in the Tenth Census 
of the United States, contains the fullest information as to the rela- 
tion of climate and soil to our cereals. From pages 10 to 27 of this 
volume I quote the following general remarks: 
We may say that, as a rule, in all former times, and until modern 
means of transportation came into use, the grain most largely con- 
sumed for bread in any country or region was the one most easily 
and most surely grown at home, or at least at no great distance away ; 
the bread, of necessity, had to be made of such grain as could be 
grown or procured with the facilities then enjoyed. Rye, buckwheat, 
oats, barley, and millet had among our ancestors an Importance as 
bread plants that they have now lost and will probably never regain. 
This fact, apparently so obvious and yet so hard to realize in prac- 
tice, lies at the bottom of that agricultural revolution already 
alluded to, which is now going on everywhere among nations and 
peoples of our civilization, and most notably in western Europe. 
Seven species (calling buckwheat a cereal) are cultivated in Amer- 
ica in sufficient abundance to be returned in the census tables, and 
three or four more are occasionally cultivated in a few localities. 
Taken altogether, these include all the more important cereals of the 
world. 
Of the seven species we have to deal with, six are natives of the 
Eastern Hemisphere and one of the western. No cultivated grain has 
originated on an island, if we except canary grass, and none in 
southern Africa or Australia, regions otherwise very rich, botanically, 
in species. Humboldt called it a striking phenomenon “ to find on 
one side of our planet nations to whom flour and meal from small- 
eared grasses, and the use of milk, were completely unknown; while 
the nations of almost all parts of the other hemisphere cultivated the 
cereals and reared milk-yielding animals. The culture of the differ- 
ent kinds of grasses may be said to afford a characteristic distinction 
between the two parts of the world.” 
The genera to which the principal cereals belong are: Oryza, or 
rice; Triticum, which includes all the varieties of wheat and spelt; 
Avena, oats of various kinds; Hordeum, the various kinds of barley; 
Secale, rye, and Zea, Indian corn. Among the true cereals—that is, 
belonging to the grass family—there are various species of millet, 
belonging to several different genera (Panicum, Pennicillaria, Emil- 
cum, Setaria, Holcus, and Sorghum) ; durra, a species of Sorghum 
