MILLER: THE PROPAGATION OF MEDICINAL PLANTS 117 
and its preparations. The value “one” represents the greatest 
toxicity, while the numerical increase indicates a proportional 
decrease in toxicity. Thus the weakest sample tested (Digitalis 
gloxiniaeflora alba) has a toxicity of 6.3. 
Another object of the Digitalis study was to test the effects of 
hybridization upon medicinal value. For this work, it was very 
desirable to bring the various species and varieties into flower as 
soon as possible. Early seed sowing augmented by a rather rapid 
growth in the greenhouse and by a slow hardy growth in the cold 
frames, as well as by a late and unusually favorable season, resulted 
in a number of flowering plants from several species and varie- 
ties (see Table II). For the purpose of obtaining early flowering 
plants upon which to begin the work of inbreeding and hybridiza- 
tion, a number of one year old plants were purchased from A. T. 
Boddington. These began flowering early, and furnished material 
throughout the season. Various combinations were tried, a 
number of which were successful, and seedlings are already being 
propagated in an effort to bring them into flower the first year. 
Thus any breeding operations can be annually continued or dis- 
continued as the results may indicate, whereas these forms under 
the usual conditions of propagation would require two years to 
reach maturity. 
It has also been noted that a small number of annual forms 
have appeared in the late plantings of several species and varieties, 
and especially where large numbers of plants were used. In all 
Cases these have been inbred. The resulting progeny of these 
inbred annuals will be closely observed for the reappearance of 
annual forms. 
Root division and propagation of lateral buds have both been 
tried with several varieties of Digitalis (see Table III). It was 
hoped that clonal varieties could be obtained in this manner. 
Uniformity of individuals and their behavior to varied soil and cli- 
matic conditions could then be studied with greater accuracy. 
Lateral buds, with and without roots, were carefully removed. 
Those removed during summer, fall and winter were extremely hard 
to start, whether they bore roots or not. Sand proved to be the 
best material for this purpose. However those made in early spring 
from plants left in the open have yielded a large percentage of 
