The Pottery Tree of Para. 49 



THE POTTEEY TKEE OF PAHA. 



BY JOHN E. JACKSON. 

 {With a Plate.) 



Amongst vegetable economic products the barks of various 

 plants bold a prominent place, whether for medicinal, manu- 

 facturing, or other purposes. The structure and formation 

 of all barks are more or less similar, though the contents of 

 the cells vary much in different plants, thus we have soft or 

 fibrous, hard or woody, and even stony barks, and the bark 

 of the pottery tree of Para is a notable example of this latter. 

 To outward appearance the formation of the bark in many 

 plants would appear to bear no relation one with another, as, 

 for instance, the cork of commerce compared with its near 

 ally, the bark of the common oak, and again with the fibrous 

 barks of many of our British trees. Naturally, the bark of 

 a tree is, at first, composed of uniform cellular tissue, 

 similar to the tissue of the central portion of the stem. The 

 formation of the layers in the fully-developed bark is on the 

 reverse system to that of the woody layers of the stem, the 

 inner portion being the most vascular, and the outer portion 

 the most cellular. Between the wood and the first formation 

 of bark lies the cambium layer, a single series of nucleated 

 cells, which originally are connected with both wood and bark, 

 and perform certain functions in the formation of the woody 

 fibres of the inner bark, and likewise in adding to the cells of 

 the medullary rays of the wood. The innermost part of the 

 bark next the wood, or rather next the cambium layer, is 

 called the liber, or endophlasum ; next to the liber, which is 

 the fibrous part, the cellular part is placed, called the meso- 

 phlaeum, or middle bark, and next that the epiphlaeum, or outer 

 bark. These three divisions are usually included under the 

 general term of cortical layers. It is from the liber, or inner 

 bark, which is composed of fibres more or less long and tena- 

 cious, that our most valuable commercial fibres are obtained. 



In some plants the fibrous system prevails through the 

 inner bark, but we shall have occasion to speak more fully 

 upon these particular kinds at another time. What we have 

 to deal with at present is a noted example of the harder, more 

 woody, or more silicious barks, which example is to be 

 found in the Para pottery tree. This is a large tree of very 

 straight and slender growth, attaining a height of 100 feet 

 before giving off any branches ; the diameter of the base is 

 seldom more than one foot, and rarely exceeds fifteen inches. 

 The wood itself is very hard, and, as will be presently seen, 



VOL. XII. — NO. I. E 



