ox THE ANATOMY OP MAGNOLIACE^E. ]^95 



nil the cells of tliis reo-ion bei no; of simihir fonn and, in most eases, 

 liavino- ])ittecl thick walls. 'I'here is not found aniono- them any kind 

 of idioblasts, whicli abound in several other genera of the same 

 family. 



The phloem portion of the fibro-vascular bundles is almost 

 destitute of hard bast, and only at the external limit of the bundles 

 are there freund a few scattered sclerenchymatous fibres, which repre- 

 sent the sclerencliymatous sheath (PI. Til, Fig. 11, .s7). The soft bast 

 certainly contains sieve-tubes, but I was not able to detect them 

 clearly. Oil-globules are often met with in the phloem region, and 

 are a j^robable cause (^f the characteristic odour wliich is given out 

 when a branch of the ])lant is bruised. In the external cortex of I. 

 'J'(ts]iirfii certain cells are met with which seem to l)e a receptacle for 

 an oily substance (PJ. 111, Fig. 12, A) ; but in /. reliijioswn the 

 existence of such cells can not be clearly detected, thoug-h some cells 

 of the external cortex may be suspected to be of that nature. In the 

 xylein there are found trachea^, fibres, and wood-parenchyma. The 

 medullary rays are very narrow, generally consisting of one or two 

 rows of cells. In /. irligiosiim the demarcation of the annual rings is 

 generally not very clear, owing to the fjict that the xylem-elements 

 formed at the end of autumn of the preceding year are similar in size 

 to tliose wliich are formed at the beginning of the next spring. 



The pith is surrounded by a medullary sheath, in which spiral 

 tracheae are found. The parenchymatous cells of the pith have thick 

 walls which are often ])itted. They are lignified in old specimens of 

 7. rclifiiosinn ; and in 7. Tasliiroi this is the case even in youn»' 

 s])eeimens. According to PrantP sclerenchymatous cells are found in 

 the pith of Illiciea?, but I do not find them in my specimens. 



I'cfiolf. — The fibro-vascular bundles of the petiole do not form a 



1. E:iiJ'l<^r uml PiMnM, />/'' initHrliclwit PtiKtr.i'iif'aiiiiUcn. 



