Fig. 13. The Development of the Guayule Plant from Seeds and from Retoños.

its business of obviating the effects of untoward conditions in its environment. We may now inquire briefly into its response to cultivation.

To introduce a feral plant into a condition of culture is not without much uncertainty as to the results. The physiological balance is frequently so disturbed as to produce marked quantitative changes in the various secretions. Thus it happens that certain drug plants when put under cultural conditions do not always produce alkaloids or other