ILLUSTRATIONS 



Plate I 



Fir,. 1. Native of Ceylon with basket made from a leaf sheath of the ai'eca 

 palm for collecting papaya latex. (Photograph by D. S. Pratt.) 

 2. Showing method of placing support and hanging basket on the tree. 

 (Photograph by D. S. Pratt.) 



Plate II 



Papain samples, illustrating various grades. (Numbers correspond to 

 text.) (Photograph by Martin.) 



Fig. 1. From local drug store. 



2. Ceylon, grade 2. 



3. Ceylon, grade 1. 



6. Ceylon, from Mead Johnson & Co. 



7. Ceylon, from Mead Johnson & Co. 



8. Mexican, from Mead Johnson & Co. 



9. West Indian, from Mead Johnson & Co. 

 10. Philippine, prepared by the author. 



TEXT FIGURES 



Fig. 1. Curve l. Papain from local drug store. 

 Curve 3. Ceylon papain, sample 3. 

 Curve U- Ceylon papain, sample 4. 

 Curve 5. Ceylon papain, sample 5. 

 Curve 6. Ceylon papain, sample 6. 

 Curve 7. Ceylon papain, sample 7. 

 Curve 8. Mexican papain, sample 8. 

 Curve 9. West Indian papain, sample 9. 

 Curve 10. Fresh papaya latex, sample 10. 

 Curve 12. Papain by alcohol precipitation, sample 12. 



2. Rate of digestion of milk protein by papain. 



3. Digestion in hydrochloric acid solution. 

 Curve 1. With 50 milligrams of papain. 

 Curve 2. With 25 milligrams of papain. 



4. Digestions at temperatures from 0° to 70°. 



35 



