ON THE ANATOMY OF MAGNOLIACEil]. l^J 



are separate at first, tend t(3 unite and form one body of xylem ; 

 but in }Iü(jnoli(( (jmuditloya they conti nne separate for a comparatively 

 long time, so that tliere remains in the central portion a mass of 

 iinlignirted cells. In KdnsJiin-iuoktircH, (a variety of MiUjnolia oJiocatti), 

 I saw only a continuous mass of ligniiied cells instead of separate 

 xylem-plates, even in the youngest s[)eciinens obtainal)le. In general, 

 the endodermis is distinctly marked off from the surrounding tissues 

 (PI. A^, Fig. 32, {'), and in most cases it is traceable even in somewhat 

 old roots. In Michelia compressa and Miujnolia coNspicua, var. pur- 

 pumscens, somewhat elongated cells with lignified walls appear \evy 

 early in the cortex (1*1. V, Fig. 32, es), while the xylem-plates still 

 remain se})arate. The widls of these cells in the latter species are not 

 uniform in thickness, the part (^f the wall facing the circumference 

 being not much lignified, while that facing the centre is thickened and 

 lignified. 



The cortex of the older root of MarpioJia Kob)is contains many elongated peculiar cells, 

 found near the intercellular spaces of schizogenetic origin, which also abound in the root of 

 this plant. 



When the roots of some species of MagnoUeœ, such as Michelia Cliainpaca, Mich, com- 

 pressa. Magnolia Kohus, &c., are kept in alcohol they impart a I'ed colour to it. 



Anatomical Characters of DifTerenl Genera Compared. 



In the fores'oino; najj'es the anatomical ch;u"acters (jf each i>'enus 

 of the present family having been described, it is now possible to 

 give a comparative view of them. The structural points to be com- 

 pared will be treated under the same four principal heads as used 

 in describing each genus : Stem, Petiole, Blade, and lîoot. 



Stem. 



The characters of the stem require fuller treatment than the rest, 

 and will be compared under the several structures. 



1 . Epidermis. — The epidermis generally consists of a single layer 



