300 



UNIVERSITY OF CALIFORNIA EXPERIMENT STATION. 



Size and weight of average specimens of principal walnut varieties. Weight in grams. 

 Volume in cubic centimeters. Dimensions in inches. 



*These samples may have been a little heavier than the average. 



In the above table a very careful effort has been made to present 

 average statistics of the varieties given. The reader should know, how- 

 ever, that this is an extremely difficult thing to do, since some of the 

 varieties mentioned perform differently in one part of the State than 

 in another, and, furthermore, nuts of the same variety vary widely on 

 trees of different ages and under various conditions in the same locality. 

 Again, especially, in regard to weight and specific gravity, walnuts 

 vary to a considerable extent from year to year. For absolutely 

 average statistics, sample nuts would be necessary from various parts 

 of the State from trees of various ages and on different types of soil 

 and from the crops of several different seasons. It is impossible to 

 obtain such samples at the present time in the case of practically all 

 the varieties mentioned. The best that we can do is to present what 

 in our judgment and as a result of our experience are fair, average 

 figures for these varieties. We have endeavored particularly to bring 

 out the comparative size and weight of the different varieties and 

 believe that the figures given are fair and representative in this respect. 

 The figures given were obtained as follows: 



Weight. Average weights were obtained by weighing large num- 

 bers of nuts, especially in the case of the more prominent varieties, and 

 averaging these. In most cases nuts of more than one season's crop 

 were included. Many weighings were also made by picking out indi- 

 vidual nuts of average size and weighing these. 



Volume. The volume was obtained by partly filling a graduated 

 cylinder with water, then immersing a given number of nuts and not- 

 ing the height to which the column of water rose in the cylinder. The 

 increase was then divided by the number of nuts, giving the average 

 volume per nut in cubic centimeters. Here, again, large numbers of 



