BY D. MCALPINE. 623 



r is conipaiabk', in this respect, to the anastomosing veins and 

 tarteries of the human body, only we must be on our guard against 

 speaking of "circulatory" tissues, or of the "circulation" of 

 water and foods, as if there were a central organ from and to 

 which the nutritive fluids were directed. On the other liand, we 

 must remember that, even in the apple, there is a connected, and 

 not a scattered system of vascular bundles (as Strasburger erro- 

 neously states), which branch out from the stalk, and distribute 

 food-materials to every part, passing along the inner wall of each 

 of the five chambers to supply nourishment to the seed, and then 

 spreading out among the cells of the flesh. 



The fruit is a kind of central dep6t, to which all the various 

 ingredients, which go to make up a perfect food, are conveyed. 

 The water containing mineral matter in solution from the root, 

 and the starch conveyed in the soluble form of sugar from the 

 leaves, meet and unite to form the organic food-supplies, the 

 so-called elaborated sap, which passes through the stalk into the 

 fruit, and there, in contact with the living protoplasm, builds up 

 new tissue. 



The fruit itself supplies an extra amount of starch, to be stored 

 up, and utilised when ripening occurs. As the fruit ripens, this 

 stored-up starch is gradually converted into sugar, and instead of 

 being sour and disagreeable, it acquires the pleasant taste and 

 delicious flavour of the world-renowned fruit of temperate climes. 

 The sweetness of an apple, however, does not depend altogether 

 upon an excess of sugar, as is generally supposed, but rather upon 

 an absence of malic acid, for sour apples are frequently found to 

 contain more sugar than fruit of a sweeter kind.* The taste of 

 an apple, therefore, will depend mainly on the diminished acidity, 

 but also partly on the percentage of sugar present. 



Thus as the result of supplies drawn from the soil and the air, 

 and distributed by means of a highly elaborate and effective 

 vascular system, there is produced the shapely, coloured, nutritive, 

 and finely flavoured apple, which contains the seed, the supreme 

 effort of the tree's existence. 



* Browne, " A Chemical Study of the Apple and its Products," p 14. 

 54 



