CORTEX CINNAMOMI. CINNAMON. 165 



Those of the secondary bark (inner bark) are usually 

 isolated or in twos; rarely in threes. The diameters of 

 the fibres of the middle bark vary from 8 to 30 microns, 

 while those of the inner bark are more or less constant, 

 1 5 to 40 microns, averaging about 3 5 microns. The length 

 of the two may be the same, 250, 400, 700, but about 500 

 microns as a general average. The lignification may 

 also be the same. The fibres of the primary bark are 

 apt to be a little longer than those of the secondary 

 bark. 



The starch is quite abundant; it is found closely 

 packed in the parenchyma tic cells of the middle and. inner 

 barks. The grains are both simple and compound. 

 The compound grains consist of two, three, or four 

 granules. The edges are rounded and the hilum is 

 generally centric, simple, or sometimes slightly radiate. 

 The grains average from 4 to 20 microns; the majority 

 measuring about 10 to 13. 



In a few cells small acicular crystals of calcium oxalate 

 are found. These are in small quantities only, and are 

 readily overlooked. They rarely are over 5 microns in 

 length. Still more seldom are small cuboidal crystals 

 associated with the fibres. These are also minute, and, 

 while seen sometimes in long sections of the bark, are 

 rarely met with in the powder. 



Mucilage cells and oil cells are frequently found. The 

 oil cells are the more prominent. They are situated 

 more commonly in the outer part of the inner bark, and 

 are quite large, being from 20 to 75 microns wide and 

 sometimes 150 microns long. In many of the dried oil 

 cells, small rectangular secretory bodies may be found. 



The powder from Ceylon cinnamon shows numerous 

 fibres and stone cells. Parenchyma and starch are not so 

 abundant. 



The powder is best studied in chloral or in a 5 per cent, 

 solution of lysol. 



