18 
then be in the form of a white or cream-colored powder, which should 
be placed in bottles and tightly closed. 
In the powdered form or as dried flakes it is exported to America 
and Europe, where it is further refined and sold as a powder or in 
tablet or other form, under various tradenames as u papoid," "caroid," 
"papain," "papayotin," etc. 
Little information is available as to yields. Some collectors figure 
upon a yearly production of 1 pound of dried latex per tree. This 
is probably rather a high estimate. The coagulated latex will pro- 
duce about 25 per cent of its weight in dried powder which still con- 
tains from 6 to 10 per cent of moisture. 1 About one-sixth of the 
dried powder is papain. 
PART II. BREEDING OF PAPAYA. 
One of the most interesting and important features of papaya 
study is breeding; interesting because of the many problems which 
it presents, and important because of the large promise of improve- 
ment in these fruits. This part of the paper will attempt to present 
descriptions of some of the material at hand for such work, showing 
also some of the difficulties, possibilities, and limitations in papaya 
breeding so far as they have appeared in the work performed here. 
BOTANICAL NAMES. 
Before entering upon these phases of the subject a word will be 
in order as to the names, botanical relationships, and distribution of 
the species. Carica papaya Linn, has been designated botanically 
under several names as Carica mamaja Vellozo (Fl. Flumin., Vol. 
X, t. 131); Carica Tiermaphrodita Blanco (Fl. de Filipinas, Gran 
edicion 1879, Vol. Ill, p. 212); Papaya vulgaris A. DC. (Prodr., 
XV, I, p. 414); and Papaya sativa Lussac (Fl. des Antilles, Vol. Ill, 
p. 45, t. 10, 11). 
COMMON NAMES. 
The species has been known under many common namjes, as tree 
melon, melon zapote, pawpaw, papaw, lechoso, maneo, mamerio, 
papai, papaya, etc. In English-speaking countries the name papaya 
is taking the place of tree melon and pawpaw, both of which are 
misleading. It is particularly desirable that the use of the name 
papaw to designate the fruit should be dropped, since its application 
to a wholly unrelated species, Asimina triloba, is well established. 
The name papaya, which now should be adopted generally, is believed 
to be of Carib origin, and is heard among the descendants of these 
aboriginal peoples in various forms, as "mapaya" and "mamaya," 
i F. B. Kilmer. The Story of the Papaw. Amer. Jour. Pharm., 73 (1901), Nos. 6, pp. 272-285; 7, pp. 
336-348; 8, pp. 383-395. 
