4 BULLETIN 803, U. S. DEPAETMENT OF AGRICULTURE. 



lated maimit from the immature olives, but more recently Hart- 

 wich and Uhlmann^ declared that its presence had not been con- 

 clusively shown, and stated that they could not detect it. These 

 authors, who followed microscopically the development from bud to 

 fruit, state that there is no starch in the olive at any stage, with the 

 exception of cells adjoining the stomata. These writers also re- 

 ported that glucose was present in almost all stages of development, 

 and they believed it to be the substance from which the oil is formed. 

 Of interest is the glucoside discovered by Bourquelot and Vintilesco ^ 

 and named by them " oleuropein." Subsequently ^ they isolated it 

 in a state of comparative purity, finding it powerfully levorotatory 

 and yielding d-glucose on hydrolysis by dilute acid or emulsine. 

 They reported it as possessing a strongly bitter taste, which is of 

 special interest, since it thus appears probable that this is the sub- 

 stance, or at least one of the substances, which gives to fresh olives, 

 both in their green and ripe state, their intensely bitter flavor, mak- 

 ing it impossible to eat them until the bitter principle has been re- 

 moved by the pickling process. Also Bourquelot and Vintilesco,^ 

 by tlie use of invertine, claim to have demonstrated the probable 

 presence of very small amounts of sucrose in the olive. 



A number of studies on the ripening of the olive in Europe are 

 given in the literature on this subject. De Luca seems to have been 

 the first investigator,^ beginning in 1861. He showed the increase 

 in the volume and weight of the fruit and that the oil increased gradu- 

 ally from the time the pit was formed. In 1878, Eoussille® pub- 

 lished analyses following the ripening and showing an increase of 

 oil in the fruit flesh from about 1 per cent in July to 34 per cent at the 

 end of November. Funaro published similar analyses,'^ tracing the 

 oil in the fruit flesh from a very low figure in the latter part of July 

 to 27 per cent in late February. Hartwich and Ulilmann, studying 

 fruit from San Eemo,^ distinguished three periods of development. 

 In the first, covering approximately July and August, the pit was 

 forming, and the oil content, on a basis of the whole fruit, increased 

 from about 0.5 per cent to 5 per cent. In the second period, Septem- 

 ber and October, the pit increased little, while the flesh and oil in- 

 creased rapidly. In the third period, from October to January, the 

 oil increased slowly until there was 30 per cent in the fruit flesh, 

 which finally declined to nearly 25 per cent in the middle of Feb- 

 ruary. De Luca had noted a similar decrease in oil at the end of the 



lArch. Pharm. (1902), vol. 240, p. 475. 



2 J. pharm. chim. (6th ser.) (1908), vol. 28, p. 303. Compt rend. (1908), vol. 147, 

 p. 533. 



»J. pharm. chim. (7th ser.) (1910), vol. 1, p. 292. 



4 J. pharm. chim. (6th ser.) (1908), vol. 28, p. 303 (7th ser.) (1910), vol. 1, p. 292. 



6 Rend, accad. sci. Napoli, for 1861 and following years (original source not available). 



6 Compt. rend. (1878), vol. 86, p. 610. 



'Landw. Vers-Sta. (1880), vol. 25, p. 52. 



