CARYOPHYLLUS. CLOVES. 225 



eter and 30 to 1 2 5 microns tangentially . Those nearer the 

 epidermis are usually smaller. The parenchymatic tissue 

 lying within the area of the oil glands is larger, the cell 

 walls are more pronoimced, and collenchymatic thickening 

 is more common, though it is not absent, for the outer 

 parenchymatic rows. -Fibro-vascular bundles are found 

 here and the tissues become lax, and large intercellular 

 spaces are prominent. The bundles are delicate, more 

 or less incomplete, contain small vessels and fibres, and 

 are, in general, of the open collateral type; bi-collateral, 

 and bimdles concentric to a central sieve portion and 

 peripheral to an outer sieve portion, are described by 

 Tschirch and Oesterle. Bast fibres are found on the 

 outer portions of the bundle. They average 40 to 50 

 microns in diameter. Closely surrounding the bast fibres, 

 usually lying between them and the vessels, small crystal 

 cells are closely clustered. A well-marked columella is 

 found in the centre of the section. It is connected with 

 the outer portions by the loose, parenchymatic tissue with 

 large intercellular spaces. The columella contains in- 

 complete fibro-vascular bundles. The vessels and fibres 

 are usually very delicate. Numerous small crystals are 

 here present. Sections of the calyx lobes show numerous 

 oil cells, with typical leaf structures. 



If sections of the hypnanthium, after previous soaking 

 in water, are placed in a low fiat dish in alcohol, or a 

 micro-slide-cell, crystalline needles of caryophyllin de- 

 velop. Similar sections placed in ofhcial potash solution, 

 and then soaked in water in a cell, show in from one to 

 two hours, the development of fine crystal needles of 

 eugenol potassium, CgH3(C,H5)OCH30K. These are par- 

 ticularly abundant in the oil reservoirs. 



Powder. — The powder of cloves is composed of a great 



many diverse elements, and its complete study is attended 



with much patient effort. The powder is dark-brown. 



It contains parenchymatic tissues, collenchyma, bast 



'5 



