CHANGES IN COMPOSITION OF CALIFORNIA AVOCADOS. 19 



store the remainder until it has softened before analyzing it. The 

 best that could be done was to select a lot containing from two to 

 six fruits, as nearly uniform as possible, analyze half this number as 

 soon after picking as possible, and hold the other half until they 

 had become soft. The data must therefore be considered in the 

 light of these facts. Where, however, changes are almost always in 

 one general direction, the probability of their being the result of 

 individual variation is remote. 



In all, 40 samples were analyzed at once and after storage, the 

 number being distributed among immature and mature fruits. Some 

 difference between the specific gravity of the fresh and storage fruits 

 of man3 T varieties is shown. In some varieties the storage samples 

 have a much lower specific gravity than the fresh, but in other 

 varieties the reverse is true. Peculiarly enough, also, the position in 

 each type when the fruits are thoroughly mature shows a tendency 

 to reverse itself. Cases in point are the Taft, six samples of which 

 were examined, and the Fuerte, eight samples of which were examined. 

 The Taft samples in September had the same specific gravity, but 

 in October. November, and December fresh samples had a higher 

 gravity than the storage samples picked at the same time, while in 

 May and June the reverse was true. The Fuerte samples for Sep- 

 tember also had approximately the same specific gravity. The 

 October, November, December, January, March, and April samples of 

 fresh fruit, however, had a lower specific gravity than the storage sam- 

 ples, while in May the reverse was true. Also in the case of the Lyon 

 the fresh samples shewed a higher specific gravity until June, when 

 the storage samples had the higher density. On the other hand, the 

 Puebla samples always showed a difference in specific gravity, the 

 soft samples having the higher. Unfortunately, the samples were 

 exhausted before thorough maturity was reached, so that any change 

 late in the season escaped observation. The December samples of 

 the Spinks showed a higher density in the fresh sample, after which 

 the reverse held true. 



Omitting the data on the Blakeman, only one double sample of 

 which w;is examined, the varieties having the heavier skins (Dickin- 

 -on. Lyon, and Taft) have higher densities in the fresh samples. The 

 thin-skinned fruits (Fuerte, Puebla, and Spinks) show a higher 

 density in the ease of the storage samples. Sharpless also is rather 

 thin-skinned, but acta in this respect like a thick-skinned variety. 



Jn several cases the pulp or edible* matter increased during storage 

 of the samples. Two factors may account for this — individua 

 variation in the fruit and inability to separate satisfactorily the 

 -kin and the pulp in the very green samples- In this connection 

 it will be noticed that the proportion of skin in the storage samples 

 is almost always lower than that in the fresh samples. Of the 40 



