The ripening process in tomatoes has been rather thoroughly studied. Sando found that tomatoes ripen uniformly, regardless of size, at a certain age, dating from the setting of the fruit. This time, which, of course, varies according to weather conditions, was eight weeks when the studies were made. Ripening is accompanied by an increase in moisture, acids and sugars, with decrease of solids, nitrogen, starch, pentisans, crude fibre and ash. Sugars increase from about a quarter to about half of the dry weight. Chemical analysis did not show differences sufficient to account for the difference in quality between vine-ripened fruit and green fruit ripened in the laboratory. Lack of ventilation seems to be detrimental. It is commonly held that tomatoes chilled without freezing will not ripen satisfactorily afterward. This belief is discounted by results of Wright and associates and of Platenius who found little effect of low temperatures upon later ripening. Wright[20] and Platenius[21] have both found that tomatoes should not be stored at low temperatures, 50° to 60° F. being best. Storage is not likely to be satisfactory for more than a month. Waxing Waxing of tomatoes by immersion in a dilute water emulsion of paraffine and carnauba waxes is being tried out with very promising results. Waxes are also dissolved in volatile hydrocarbons and sprayed on. Moisture loss and shriveling are materially retarded, and interference with the ripening process is negligible. The wax coating is very thin, adds an attractive gloss and is entirely harmless. [Illustration: FIGURE 19.--Packing tomatoes on a farm in Connecticut. Boys in the background are wiping and sorting. The others are packing in half-bushel boxes. The top slats are put on before packing and the bottom is nailed on at the finish of the job. A board which is turned over with the box keeps tomatoes from falling out.] Grading It is generally true that at market the poorest products in a given lot tend to fix the price. When the buyer finds a few inferior specimens he assumes there are many more. Imperfect and diseased specimens infect others. Grading enhances the appearance of the pack. [Illustration: _Courtesy Tripak Mach. Service_ FIGURE 20.--A California packing house with elaborate machinery and fully organized.]