Page:The Olive Its Culture in Theory and Practice.djvu/161

Rh Whence it is clear that in the berry the quantity of water after the tenth of September diminishes gradually. From 59.73 per cent. it falls to 48.35 by the end of February thus losing about 19 per cent. or one-fifth of its weight. The percentage of oil, especially of the pulp, increases notably from the end of September to the end of November, but after this time the increase is small. The Italian country folk have a proverb which justly says: "At Santa Reparata (8 Oct.) every olive berry is oiled." From this time the pulp grows softer, and squeezed between the thumb and finger, some little globules of oil can be seen.

By the investigations of Signor Harz, of Vienna, confirmed by those of Roussille, it has been shown that the fatness of the olive is formed in little special cells of secretion precisely as the chlorophyl or green coloring matter is evolved and these are distributed through the berry side by side. When the fruit is still young these cells contain a material which is not fatty, nor is it starch, or any of the hydrates of carbon similar to these substances but instead is charged with nitrogen and contains a substance which in the process of ripening, takes on the character of a tough gum, wax, and fat. Finally this compound material, as maturity approaches, liquifies becomes oil and working from the inside, outwards, the membranes of the little cells themselves are gradually dissolved and the berry is filled with oil.

Messrs. Roussille and Funaro have also discovered that while the fatty material of the pulp is always on the increase up to maturity, that of the leaves on the other hand, is almost constant and always in such quantity as to overthrow the belief that there may be any connection whatever between them. The former undoubtedly is formed in the berry as Harz discovered by microscopical observation.

Funaro has further proved that the sugar of the leaves only appears when the oily substance is perfected, that is to say when the plant is near the term of its vegetative period and the fruit is well