138 SORGHUM. 



the crop on strong soils, and in favoring circumstances, and it is not ad- 

 vised that they be thrown away, but that they only be used in tlie 

 manufacture of syrup. 



EFFECT OF REMOVING SEED DURING DEVELOPMENT OF PLANT. 



During the experiments upon sorghums grown on the grounds of 

 the Department for tlie past five years, much annoyance has been oc- 

 casioned by the multitude of English sparrows, and it was almost im- 

 possible to save any seed from the crop, except of such varieties as 

 appeared less attractive to tiiese birds, or from such panicles as were 

 protected against iheir invasions. It was at least a matter of doubt 

 whether this removal of the seed during the plant's development had 

 not had an effect upon the sugar content of the juices, since, as is ob- 

 vious, the production of the seed is at the expense of constituents of 

 the juice of the plant; and if this process is arrested by any removal 

 of the seed before reaching maturity, it would appear natural to expect 

 some result upon analysis of the juices of such plants. 



That such a view has widely obtained, among those engaged in the 

 investigation of the producticm of sugar from sorghum and maize stalks, 

 is clear from the advice frequently given to remove the ears of corn so 

 soon as they appear, if the maximum amount of sugar in the juice from 

 the stalks is desired. ^'^ 



For the purpose of securing the seed of the new varieties from 

 Africa, India, and China, as also to learn whether to any extent my 

 results in past years had been vitiated by these depredations of the 

 birds, care was taken, in 1882, to protect certain panicles of each va- 

 riety grown, so soon as they came into blossom, by enveloping them 

 in bags made of tarlatan. In this way I was able to secure well 

 developed heads of each, fully ,set with seed. 



* Professor Weber reports the followinp; analj-ses made of two stalks of sor- 

 ghum, which had been planted at the same time; but the one, A, had been 

 topped while it was in blossom, while B, had been allowed to retain the pani- 

 cle, and the seed was in the condition of " hardening dough : " 



A. Sucrose, 12 G2 per cent, Glucose, 2.58 per cent. 



B. Sucrose, 7,80 per cent, Glucose, 4.80 per cent. 



There was a corresponding increase in specific gravity. 



Tills is an important result, and apparently indicates that the production of 

 the highest content of sugar is incompatible with the production of grain; and 

 since the grain is alone sufficiently valuable to pay all the expense of culti- 

 vating the crop, it will be admitted, as most desirable, that this question, as to 

 the practicability of the two crops of grain and sugar, be set at rest by decisive 

 experiments. 



