70 



SEEDS AND SEEDLINGS 



smaller and quite irregular, having large holes in them. We know 

 that the germinating grain has a much sweeter taste than that 

 which is not growing. This is noticed in sprouting barley or 

 malt. We shall later find that, in order to make use of starchy 

 food, a plant or animal must in some manner change it over to 

 sugar. This change is necessary, because starch cannot be ab- 

 sorbed by the young plant, while sugar can be thus taken in. 



A cornfield, showing staminate and pistillate flowers, the latter having become 



grains of corn. 



A Test for Grape Sugar. Place in a test tube the substance to 

 be tested and heat it in a little water so as to dissolve the sugar. 

 Add to the fluid twice its bulk of Fehling's solution, 1 which has been 



1 To make Fehling's solution (so-called after its discoverer), add to 35 grams of 

 copper sulphate (blue vitriol) 500 c.c. of water. Put aside until it is completely 

 dissolved. Call this solution No. 1. 



To 160 grams of caustic soda and 173 grams of Rochelle salt add 500 c.c. of 

 water. Call this solution No. 2. 



For use mix equal parts of solution 1 and 2. 



The following formula is also convenient : 

 I. Copper sulphate : 9 grams in 250 c.c. water. 

 II. Sodium hydroxide : 30 grams in 250 c.c. water. 



III. Rochelle salt: 43 grams in 250 c.c. water. 



For use add to equal parts I, II, and III, two parts of water. 



