434 CONSERVATIVE ORGANS. [LECT. VIII. 



chiefly of oblong cells, or rather short hexa- 

 gonal tubes. These tubes in the transverse section 

 appear arranged in beautiful rays proceeding from 

 the centre to the circumference, and, in the lon- 

 gitudinal section, show nearly the same symme- 

 trical ranks that have been described as exist- 

 ing in the Poppy root. The sap vessels are com- 

 paratively few in number, and are arranged in rays 

 through the central part. They are larger than the 

 cellular short tubes, which are condensed in the 

 line of each ray of sap vessels, so as to produce a 

 very beautiful appearance in a transverse slice of 

 the root examined under the microscope. All the 

 sap vessels are punctuated, but I have not been 

 able to satisfy myself that they are spiral. In the 

 second year, a new circle of short tubes is formed 

 with Some additional sap vessels interspersed 

 through it, both preserving the radiated arrange- 

 ment ; the old bark appears lacerated, shrivelled, 

 and pushed outwards, whilst the space betwixt it 

 and the new central matter, is filled up with fresh 

 cortical cells. 



The short tubes appear to be the principal re- 

 servoirs of the mucus, with which this root 

 abounds ; but it is present in the cortical cells also, 

 a lateral communication existing between these 

 and the hexagonal tubes. It is apparently in- 

 tended for advancing the fructification of the 

 plant, being gradually absorbed as that process is 



