420 FARMERS' INSTITUTES. 



the end of the season. Unhappily the sorghum sugar worker has no such 

 assurance. The same variety of cane, in the same degree of maturity, and 

 often in the same field, will show the most surprising differences in the 

 Bugar content of its sap. 



M. Leplay has called attention to the gradual deterioration of sorghum 

 wheh grown successively for a number of years in France, and ascribes it to 

 admixture with broom corn. This deterioration of the cane, however, has 

 been noticed where no admixture with broom corn has been possible. At Rio 

 Grande the average percentage of sugar in the amber cane when first grown, 

 six years ago, was 11; during the year 1886 it was less than 6 per cent. In 

 several hundreds of acres of this cane, the Juice was so poor that no attempt 

 was made whatever to convert it into sugar. 



These remarkable variations in the content of sucrose in sorghum cane, 

 and the fact that what sucrose is present in certain common circumstances is 

 likely to rapidly suffer inversion, are points which render it impossible to 

 predict in any given case, financial success in attempts to manufacture sugar. 

 Looked at from the side of physiological botany, this tendency of the sucrose 

 in sorghum to rapid change is of great interest. The question naturally 

 arises, is the sucrose of sorghum a plastic material, a reserve material, or 

 waste. It is not probable, from reasons which I give in the paper of which 

 this is an abstract, that the sucrose in sorghum is a plastic material. Is it a 

 reserve material? The sucrose which is deposited in the seeds of plants, in 

 tubers like the sugar beet, and in sugar cane, is doubtless a true reserve 

 material, and, by its decomposition, helps the growth of the succeeding 

 plant. But the sucrose in sorghum seems to have no such function. It can 

 in no way aid the incipient growth of the next plant, for that plant grows 

 from a seed. As far as any use in the economy of the plant is concerned, 

 the sugar in sorghum appears to be absolutely worthless. It seems, there- 

 fore, that the sucrose in sorghum is purely a waste material, as much so as 

 an alkaloid or a resin. In the cases where sucrose is a true reserve material, 

 as in seeds, in tubers, and in sugar cane, we find there is no tendeacy for it 

 to disappear until the needs of the new plant require it. The sucrose 

 remains, for instance, unchanged in the sugar beet until the new growth 

 begins. The same is true in a high'er degree, of the sucrose in seeds. The 

 fact, therefore, that in sorghum all traces of sucrose may disappear in a few 

 days, shows that its office is radically different. The development of sucrose 

 in sorghum is an accidental function, or, rather, an adventitious function. 

 It goes on nsnsdly pari 2}assu with the formation of the starch in the grain, 

 and the content of the sucrose in the plant, and its quantity is at a maximum 

 at the time its starch formation is completed. The chief cause of the varia- 

 tion of the sucrose in the sorghum, therefore, -is found in the accidental or 

 adventitious nature of its formation; in other words, its independence of 

 the life history of the plant. These variations in the content of sucrose, due 

 largely to the causes above mentioned, are one of the chief obstacles hinder- 

 ing the financial success of the sorghum sugar industry in this country. 



YIELD PER ACRE. 



In the same manner in which I collected the analytical data which have 

 been given, I have compiled the reports of the yield of clean canes per acre. 

 The data thus collected extend over a number of years, and represent the 

 average product of many thousands of acres. 



