ON THE ANATOMY OF MAGXOLIACE^. HJ 



riiatf^is ül)re" is used in the same sense as bast-fibre, and '• sclero- 

 blast" in that of stone-cell; when either indefinitely is to 1)e 

 denoted, the expression " sclerenchymatous element" is often used. 

 Bv "sclerenchymatous sheath" I mean the single mass of sclerenchy- 

 matous fibres, or the numerous isolated groups of them, which lie at 

 the external limit of the fibro-vascular bundles and form a rino- 

 either continuous or interrupted at intervals. I consider this sheath 

 to be ÎI part of the bundles, and not an independent structure lying 

 outside them. By " cortex" I mean all the tissues which lie outside 

 the cambial zone. That part of it which corresponds to the phloem 

 (including the sclerenchymatous sheath, when this exists), I generally 

 call the •' inner cortex "; and all the parts outside this, the "outer" 

 or "external cortex." In the case of very young roots 1 mean by 

 "cortex" all the tissue lying outside the endodermis. 



In the following pages the anatomical characters of each genus 

 will be first described, and then com])ared. It might a,])|)ear sufficient 

 to have compared at once the characters of the different generu 

 without giving a- special description of each genus, but this would 

 haA'e led to confusion, as well as to the omission of many interesting 

 isohitcd facts. 



Anatomical Characters. 



Under the headings. Stem, Pclioh', Blade, and Boot, the points of 

 structure peculiar to each are descrilied, while under the first are 

 given also those points common to all four. 



Tribe I. Trochodendreae. 



This tribe consists of three genera, species of each of which I 

 examined. 



