43 
5. Hermaphroditism. — The reasons for preferring hermaphrodite 
stock have already heen pointed out. The stocks may continue to be 
gynodicecious 1 and to a very limited extent even trioecious, 2 but the 
number of male trees can be kept very small. 
6. Suitable size in fruit. — The size that will be most desirable will 
depend upon the purpose to which the variety is to be put. For 
home use or for the fresh fruit market the extremely large varieties 
are not popular, and the breeder of table varieties will not, therefore, 
attempt to originate such forms. On the other hand there is a place 
for these, if the fruit is to be grown as feed for poultry or other live 
stock. For papain production, other things being equal, the large 
fruit would be best. 
7. Yield in papain. — Where the production of papain is made an 
industry there can be little doubt that the average yield of this drug 
could be very greatly increased by judicious breeding. 
S. Uniformity of shape. — The breeder must seek to establish varie- 
ties in which there will be reasonable uniformity of shape as well as 
symmetry and smoothness. It is not necessary that all varieties 
be alike, but there must be uniformity in pack. In breeding from 
hermaphrodite trees there will be a large number of pistillate trees in 
the offspring. Although the long form is not necessarily confined to 
the hermaphrodite tree, as pointed out above (see p. 34), nevertheless 
pistillate trees do not usually yield fruit of this shape. For this 
reason the breeder may think it best to work for two forms of fruit — 
the long, tending to cylindrical, for the hermaphrodite, and the 
obovoid for the pistillate. The fruits of such an orchard would be 
packed as two varieties. 
9. Uniformity in ripening. — This is an important- consideration. 
Some papayas ripen and decay at the outer end or the point while 
the inner half near the stem is too green to be eaten. The ideal 
papaya in ripening shows its first yellowing along the ribs about 
midway of the fruit and ripens uniformly toward each end. 
10. Coloring before softening. — Some fruits ripen with very little 
color, while others acquire a beautiful golden yellow when still hard, 
and may be kept for several days. The latter are so much more 
attractive on the table and in the market that they should be sought 
after in breeding. 
11. Color of flesh. — Those of pale whitish flesh must give place to 
the fruits of yellow, pink, or red color within. Recently some have 
been grown at this station with a quite decidedly reddish hue. 
1 2. Easily separable placenta. — If the placenta adheres tightly to the 
inner portions of the fruit and is more or less buried in the flesh, it is 
difficult to remove the seeds without marring the appearance of the 
1 Containing hermaphrodite and pistillate individuals. 
2 Containing hermaphrodite, pistillate, and staminate individuals. 
