THE ALCOHOL INDUSTRY. PART I. 191 



The processes by which the starch is converteii " into sixcrose are not clearly- 

 understood. Brown and Morris*^ believe that sucrose is the primary carbohydrate 

 synthesized by the chloroplasts. As such it may find its way directly into the 

 fruit of the coconut and other palms. In the case of the date palm, where large 

 quantities of sucrose, glucose, and fructose are stored in the fruit, Vinson " 

 suggests that maltose is the sugar which passes into the fruit, since it will 

 encoimter a relatively low osmotic pressure, or none at all, while the other 

 sugars must enter against a relatively high pressure. 



However, in the buri, the sucrose of the tuba is formed from the storage 

 material, starch, which is thus converted into the transportation material. 

 Maltose might here be an intermediate product. The question of the occurrence 

 of maltose has not been especially investigated, but from the many analyses which 

 have been made it is evident that it can be present only in inconsiderable 

 quantities, for the reason that the saps as they drop from freshly cut stems 

 contain, at most, only traces of reducing sugars. Sucrose is known to be the 

 moving carbohydrate in many plants other than the palms. As such, it is not 

 available for the nutrition of the protoplasm but must first undergo hydrolysis. 

 The conversion of the starch into sucrose might be accomplished by means of 

 diastase, with maltose as an intermediate transitory stage or by means of the 

 protoplasm itself. A diastase was found after many tests. 



The early failures to detect diastase were probably due to the sampling 

 of the trunk at points where the diastase did not exist or was not readily 

 detected. As the sap flow goes on, the starch of the trunk disappears 

 from the top down (and also, perhaps, more slowly from the outside 

 toward the center) and there may be, and probably is, a moving zone 

 where the conversion of the starch into sucrose takes place through the 

 influence of the diastase. 



St. Jentys ** has found that the diastase in leaves is formed only in small 

 quantities as it is required. 



In his investigations of the banana and the mango, H. C. Prinsen Greerligs " 

 found that the starch of the ripening fruit changes into sucrose, and while 

 evidences of diastatic action was obtained he believes the conversion of starch into 

 sucrose is a vital process and not a consequence of the action of some ferment. 



The sap contains no diastase. 



Experimental. — The slices of the stem which were daily removed to 

 maintain the sap flow were repeatedly tested for starch and for a diastase 

 with negative results. The sap was tested on several occasions for a 

 diastase and none was found. The iodine test was always employed for 

 the recognition, of starch, and it is therefore possible that minute quan- 

 tities were overlooked. In only a few cases was the microscopic identi- 

 fication resorted to. Tests for a diastase were made by maintaining 

 at 55° a mixture of 25 cubic centimeters of a 2 per cent starch solution 

 and from 5 to 10 grams of the substance to be tested for a period vary- 



"Journ. Ghem. 8oc. London (1893), 63, 673. 

 "Bat. Gaz. (1907), 43, 398. 



"Green. The Soluble Ferments and Fermentation, Cambridge (1901), 21. 

 '^ Arch. Java Sucker Ind. (1908), 267; and Intern. Sugar Journ. (1908), 10, 

 372 through Ghem. Abstr. (1908), 3, 2964 and 3414. 



