14 CITRUS TREES AND THEIR DISEASES 



We go back now to this receiving agency and we 

 find that the nutritious matter gathered by the many 

 feeders is being transported to the base of the tree 

 through this base root and there comes in connection 

 with the mechanical action of the tree, which forces 

 its way through the many sap cells or channels of dis- 

 tribution, passing through the body up to where the 

 branches branch out. There it comes in contact with 

 the distribution agencies, which send it further on 

 through the branches to the twigs, through the twigs 

 to the stem of the foliage, distributing its proportion 

 of nutritious matter from the many channels or cells 

 to all parts of the top of the tree. 



The writer, in his close study of the anatomy of 

 the tree finds that each base limb and each branch 

 leaving this base limb is spread through separate cells 

 or channels of distribution of sap. Therefore one base 

 limb may die from injury or some other cause and not 

 affect the next limb or branch. The writer has gone 

 into this particular study so carefully he has been able 

 to know, or perhaps almost correctly if not quite, the 

 number of sap cells passing through a three year old 

 tree and through its distributing agencies, which took 

 him months of careful study and with the strongest 

 glass to be found, as these sap cells are very, very small 

 channels. In some varieties of trees they are much 

 larger than in other varieties where sap is heavier 

 and trees grow larger. 



With the citrus tree the writer finds the sap so 

 much heavier than that of the apple. I desire the 

 reader to understand right here that the writer has 



