AND HIS PLANT SCHOOL 



171 



that time nuts were considered unwholesome. They were 

 not eaten as daily food, for those then offered for sale, in 

 the stores, were tough; the kernel was sometimes covered 

 with mould; the skin over the kernel was dark and con- 

 tained a large amount of tannin, a chemical substance 

 used in tanning leather. This tannin caused the mouth 



to smart and burn when the , , 



nut was eaten. But, worst 

 of all, many of the nuts had 

 worms in them and could 

 not be used at all. The 

 nuts then raised in Cali- 

 fornia were of different sizes 

 and shapes, and many con- 

 tained the puckery tannin. 



While searching for a 

 better nut to train, the 

 master heard of a tree in 

 the business section of San 



Francisco which bore delicious nuts in abundance. The 

 tree was to be immediately destroyed, as the ground was 

 needed for building purposes. He purchased the last crop 

 of nuts which this valuable tree produced, every one of 

 which was planted. 



The trees resulting were mostly quite ordinary, but two 

 or three bore nuts in every respect even better than the 

 nuts produced by the original tree. From the best two of 



Santa Rosa walnut. 



