ARTIFICIAL RIPENING 143 



"The second phase is the real ripening; it consists 

 of complex chemical transformations. The cane 

 sugar becomes invert sugar and the free tannin is 

 deposited in insoluble form in the giant cells which 

 Tichomirow, Kearney and Lloyd have described. 



" Botanical maturationis simply accomplished with 

 the aid of a sufficient amount of heat, an amount so 

 large for late varieties that it is reached only in 

 regions having an extreme desert climate. 



"On the contrary, in the real ripening humidity 

 plays an essential part. One cannot ripen dates 

 artificially either by incubation or by the slow system, 

 if the atmosphere is dry. In artificial ripening, the 

 air which surrounds the dates must be saturated 

 with the humidity which the dates give off as they dry 

 and wrinkle. The packing cases in which Deglet 

 Nur dates are sent from the oases to Biskra, Algiers or 

 Marseille contain a mixture of loose dates and dates 

 on the branch, so that the space between these 

 branches is occupied by moist air. Deglet Nur 

 can ripen on the tree in many oases of the Algerian 

 and Tunisian Sahara; but in the extreme autumnal 

 aridity of the deserts of the southwestern United 

 States, it can not do so on the tree. The dates 

 reach their full size in September or October, then 

 dry on the tree, wrinkling more or less. There 

 results a date which more resembles dry dates like 

 Makantishi than Deglet Nur as it is known in Algeria 

 and Tunisia,"* 



What Mr. Swingle says of dates shriveling and 

 hardening on the palm applies especially to Deglet 

 Nur, yet dates of all varieties have been found to give 



*Dates in such a condition should be soaked in water for two 

 days and then treated as for rapid ripening. 



