ON THE ANATOMY OF MAGNOLlACEiE. ^47 



since there exist in other anatomical characters of these tribes such 

 marked diiferences as those which I have pointed ont. Thns, then 

 from a ])nrely anatomical point of view, Magnoliece and Schizmidrece 

 may be taken without any impropriety to be two distinct groups. 



In JUicieœ the only two genera, lllicium and Diiiiiiis^ whicli I 

 examined, are markedly different in some points, though similar in 

 general structure. On the one hand, the semicircular arrangement 

 of the fibro- vascular bundles of the petiole allies this tribe t(3 Scliizan- 

 dreœ, and cm the other hand, the existence of resin-sacs in Drinujs, and 

 probably in some species of lllicium, allies it to Magnolieœ. Still the 

 tribe lUicicœ is widely separated from these two tribes b}" the absence of 

 certain anatomical characters possessed by one or the other of them : 

 for instance, both the mucilage-canals and crystal-bearing sclerenchy- 

 matous elements of the Scliizandreœ, and the diaphragms and scleroblasts 

 which are found respectively in the pith and in the outer cortex of 

 Maijnolieœ, are wanting. Tluis, here again is a tribe which may be 

 anatomically considered as a distinct group. 



The wood in Driniij.s is almost exclusively made up of tracheïds, 

 and the leaf-petiole has its tibro-vascular l^undles arranged in a, semi- 

 circle, points which ally this genus to Trocliodeudron in another 

 tribe. Thus lllicic<v and 'irochodcndrcœ might seem to l)e C(jnnected 

 throufjh these two genera, were it not that the very characters that 

 ally TrochodendroJL to JUicieœ, widely separate this genus from Eiiptekea 

 and Cercidipliyllinn, the other two genera of Trochodoidnui'. Further, 

 these other two genera- are not only but slightly related to each other, 

 but are also destitute of any anatomical characters that may serve to 

 connect them with the members of the other tribes. Such being 

 the case, it is evident that the tribe TrocJiodcndreœ is very indefinite 

 in its anatomical characters, and that on these grounds Ave ought to 

 place Trochudcndron in the JlUciea', and establish a new tribe, Eupieleii'^ 



