4 Dr. Willshire's Contributions to Structural Botany. 



appearance : the cells of which they are composed are devoid of 

 colour, save the four central ones, which are filled with a yellow- 

 ish green or brown fluid ; the fourfold development of the cells 

 appears to be derived from the transverse and longitudinal di- 

 vision of a primordial cell. Beneath the scales is the epidermis, 

 which is composed of a thin cellular tissue, having sinuous walls, 

 next to which is a layer of cellular and parenchymatous matter, 

 whose cells are more or less filled with green, and sometimes 

 purple colouring matter ; next, and forming the centre of the 

 stem, is the woody tissue, which is composed of a fine, rather 

 tough, cordlike, and dark-coloured bundle of woody fibre or 

 liber cells, having a very few excessively delicate spiral vessels, 

 the spire of which, however, I have not succeeded in unrolling : 

 the whole of the woody matter is of a bright yellow brown 

 colour by transmitted light. In the leaves the central cord 

 separates into smaller ones, which run parallel with the edges 

 of the foliaceous expansion. It is in the pericarp, however, 

 that the particular form of tissue exists to which I at first al- 

 luded: if the inner brown-coloured portion of this organ, 

 which easily separates in the dry state from the external and 

 lighter-coloured layer, be examined, it will be found that it 

 consists of three distinct layers of tissue, the central one of 

 which is very distinct from the others ; the upper and under 

 layers are composed of cellular tissue, possessing no colouring 

 matter in the cells, at least in the state in which I have had 

 an opportunity of examining it ; the upper or most internal 

 one being very thin and delicate : between thsm is placed a 

 series of longitudinal fibres or hollow cellular bands, connected 

 together by a great number of small parallel transverse ones, 

 which latter have elongated oval spaces between them. These 

 series of anastomosing bands appear to be perfectly continuous 

 w r ith each other ; at the inosculating places of the transverse 

 with the longitudinal ones no septa or partitions exist, and 

 the central hollow of the fibres is like that of a single though 

 variously divided tube. It is from this layer that the deep 

 brown colour of the inner surface of the pericarp is derived, 

 every band or fibre being filled and extended by a brown 

 colouring matter. In the spaces intervening between the 

 transverse bands the colourless membrane of the cellular lay- 

 ers is distinctly seen ; a large transparent globule I have also 

 generally observed lying in the centre of the spaces referred 

 to. Now if this structure is to be referred to that form of 

 tissue called cellular fibrous tissue without membrane, it cer- 

 tainly can only be regarded as a variety of structure not indi- 

 vidually noticed before ; but I am inclined to believe it is other- 

 wise, and that it is a form having its origin in a manner quite 



