II. Elementary species in nature. 32
_Viola tricolor_, _Draba verna_, _Primula acaulis_, and other
examples. _Euphorbia pecacuanha_. _Prunus maritima_. _Taraxacum_ and
_Hieracium_.
III. Elementary species of cultivated plants. 63
Beets, apples, pears, clover, flax and coconut.
IV. Selection of elementary species. 92
Cereals. Le Couteur. Running out of varieties. Rimpau and
Risler, _Avena fatua_. Meadows. Old Egyptian cereals. Selection by the
Romans. Shirreff. Hays.