thenium incanum), does not produce retoños, as does the guayule, but sends up each season new shoots from the base of the trunk. These shoots root independently and in the course of events are separated by a constriction of the connecting tissue from the parent plant so that an old mariola plant is really a cluster of partially or wholly independent individuals. Such behavior is absent from guayule under normal conditions, but may be readily induced under irrigation, and in this way there is afforded the means of vegetative propagation which stands in lieu of the usual method of making cuttings, which has not been found possible up to the present.
The question which many will ask, whether it will pay to cultivate guayule, must remain, for the present, unanswered. That guayule may be propagated under cultural conditions, both by seed and vegetatively, has been demonstrated. That there are immense areas adapted to guayule and now almost profitless is almost equally sure. The problem seems to be how to get the plant started and to determine to what extent temporary irrigation, by manipulation of the run-off, will be justified on practical economic grounds. An experiment of large scope could be conducted so as to answer these questions and might reveal a new means of increasing our resources.
