102 PRACTICAL BOTANY 



3. Cortical tissue, with large mucilage cells. 



4. Hard bast, consisting of long fibres. 



5. Soft bast, thin-walled elements with much 

 protoplasm. 



6. Cambium, a misty band ; cells not easily defined. 



7. Xylem, with thick lignified walls, the vessels 

 appearing as large tubular cavities. 



8. Pith, parenchymatous ; its appearance as in 

 transverse sections. 



Note the medullary rays, which appear as narrow 

 bands of parenchyma, following the plane of section. 



Examine these several tissues in detail with a high 

 power. 



1. The epidermis, when still persistent, shows the 

 same characters as are observed in transverse sections. 



2. The cork is composed of square cells arranged in 

 radial rows, which are continuous through the cork- 

 cambium to the phelloderm, the latter presenting 

 much the same appearance as in transverse section. 



3. The cortical tissue, which is parenchymatous 

 throughout, also appears much the same as in transverse 

 section. 



4. The hard bast consists of long fibres, with thick 

 walls, and very small cell-cavity : they are distributed 

 in irregular groups among 



5. The soft bast, which is characterized by thin walls 

 and protoplasmic contents, and is composed of 



a. Sieve-tubes, which are best seen in the part of 

 the phloem nearest to the cambium : they resemble 

 in the main, those of Cucurlita (p. 113), but are not so 

 wide ; the sieve-plates are oblique, and face the radial 

 planes. This is the usual arrangement of sieve-plates 



