July, 1921] BALL — RELATION OF BOTANY TO HUMAN WELFARE 
caceae (laurel), Leguminosae (lupines, loco weeds, milk vetches, vetches), 
Liliaceae (cannas, lilies), Loganiaceae (strychnin), Poaceae (grasses), 
Ranunculaceae (aconite, buttercups, larkspurs), Solanaceae (belladonna, 
henbane, nightshade, tobacco), Umbelliferae (hemlock), and Urticaceae 
(nettles). This takes no account of the many poisonous fungi, especia lly 
among the fleshy fungi, or mushrooms. The interested reader is referred 
to the comprehensive manual of poisonous plants by Pammel. 
Fibers 
The most important fibers are cotton, of the Malvaceae or mallow 
family, and flax, belonging to the Linaceae. In addition are hemp, of the 
Cannabinaceae ; jute, representing the Tiliaceae; sisal, of the Amarylli- 
daceae, and abaca, or Manila hemp, belonging to the Musaceae or banana 
family. 
Forest Materials 
The two most important families producing forest materials in the 
temperate zone are Pinaceae, including pine, spruce, hemlock, fir, cypress, 
and juniper, and the Fagaceae, containing the oaks, beeches, and chestnuts. 
Others of importance are Juglandaceae, walnuts and hickories; Acer- 
aceae, maples; Fraxinaceae, ashes'; Betulaceae, birches; and Poaceae, in- 
cluding the bamboos. In the tropics many other families furnish materials 
of high value. 
Botany and Crop Improvement 
We have seen that the improvement of our present crop plants, or the 
finding of new ones, is a most promising means of increasing the food supply. 
The wide taxonomic distribution of the plant families so important to human 
welfare is an earnest of the complexity of the botanic problem involved. 
All phases of botany, including taxonomy, morphology, physiology, ecology, 
genetics, and pathology, must contribute largely if substantial progress is 
to be made. Ecology and pathology are to have full discussion elsewhere on 
this program. 
Taxonomy 
The fundamental contribution of plant classification and description 
to human welfare has been the presentation of the vegetable kingdom as a 
fairly orderly series of evolving forms rather than a conglomeration of 
wonderful but unrelated organisms. The applications of this knowledge of 
relationships are many, varied, and valuable. Through such knowledge we 
are able to build up large plant industries with an assurance of success 
which otherwise would be impossible. 
The classification of crop plants, when accomplished with the same 
precision and thoroughness which have been used in the case of wild species, 
will be of inestimable value to science and to humanity. The same prin- 
ciples will be applied, the same characters used, and the same results ob- 
