1900] MICROSCOPICAL JOURNAL. 67 



crystals; the nature of the cell contents in the different 

 parts of tlie primary cortex. In the secondary cortex, in- 

 cluding the phloem, should be ohserved: — Its width, the 

 width of the phloem rays ; the frequency, width, and di- 

 rection of the medullary rays ; the presence and location 

 of bast fibres ; the presence and location of other sclero- 

 tic elements in the phloem ; the presence of sieve ele- 

 ments, and the proportion and arrangement of phloem 

 parenchyma accompanying them ; the presence and loca- 

 tion of laticiferous vessels ; the nature and quantity of 

 cell contents, particularly the presence of crystals and 

 their form and size. After the cambium would be noticed 

 the xylem ; the kind and proportion of xylem fibers ; the 

 size, proportion, kind, and arrangement of the vessels 

 when present ; the presence of wood parenchyma, its pro- 

 portion and distribution ; the presence of specialized cells, 

 with their contents; the medullary rays, their frequency, 

 width, and contents. When vessels are absent from the 

 xylem particular care should be taken to notice whether 

 the xylem is composed of fibers only, or whether tracheids 

 are present, and to what extent ; also the character of the 

 fibers should be determined. This, of course, can only 

 be accomplished by the examination of longitudinal sec- 

 tions. If a pith is present the character and contents of 

 its cells should be noted, as well as the presence or ab- 

 sence of phloem strands, indicating bicollateral bundles. 

 The foregoing sketch refers more particularly to struc- 

 tures in which a more or less concentric arrangement of 

 the tissue systems prevails. Any eccentric arrangement 

 of the tissues should be particularly recorded. If the 

 fibro-vascular elements are s-.attered it should at once be 

 ascertained whether the section is dicotyledonous or mon- 

 OGotyledonous, or whether it belongs to the Pteridophyta. 

 In the case of monocotyledons the outer integument 

 should be observed ; the presence or absence of fibro-vas-. 

 cular bundles in the cortex, their frequency, if present, 



