112 MISSOURI BOTANICAL GARDEN BULLETIN 
moist atmosphere maintained by sprinkling overhead, and 
the temperature kept at 60-65° F. As soon as the cuttings 
root they should be potted. 
Another method of increasing the stock of any desired 
variety is to cut large tubers into parts, each of which con- 
tains a bud. This should be done in the spring, and the 
treatment thereafter is similar to that for the tubers. A 
necessary precaution in this method is to dip the tubers into 
slaked lime or charcoal to hasten the healing of the cut. 
Hybridization —The raising of new varieties from seed is 
a most interesting occupation. The grower’s enthusiasm is 
somewhat dampened at the start by the uncertainty of re- 
sults, but the variety and brilliance of the flowers are hardly 
to be equalled by any other plant. The operation itself is 
simple. The female parent is chosen and the stamens are cut 
off before the pollen is ripe, and the flower enclosed in a 
small waxed paper bag to prevent any foreign pollen from 
settling on the stigma. The male flower may also be enclosed 
in a similar bag to avoid the intermixing of pollen from 
other plants by insects. As soon as the stigma of the female 
plant is ripe—which can be told by the protruding of little 
hairs upon it—the pollen of the male plant may be brought 
to it by means of a camel’s-hair brush or forceps, this being 
best accomplished in the middle of a bright day. In a day 
or two the stigma will turn brown and ually die away, 
thus indicating that fertilization has taken place. <A pod, 
which is soon formed, bursts at the top when ripe, and the 
seeds fall to the bottom of it. Some difficulty is experienced 
with the double flowers. Very often these fail to produce 
pollen, as the pollen-bearing stamens may have changed into 
tals. This condition may be avoided, however, by starv- 
ing the plant, that is, reducing the water supply, thus forcing 
the flowers to be smaller and sometimes changing them into 
single flowers with some pollen-bearing stamens. This pro- 
cedure is not always successful, however. 
PAPAWS! 
Of all the important native fruits of the United States, 
the least known is probably the papaw, which flourishes in 
the forests of the southern part of the Mississippi valley, 
and extends west to Oklahoma and north to Michigan and 
* The numerous papaw trees in the region reached by the BULLETIN 
warrants the reprinting of the following article from the July number 
of the “Journal of Heredity” (organ of the American Genetic Associa- 
tion), Washington, D, C, 
