8 WRIGHT : THE GBXUS DIOSPYROS 



by Parmentier contains a general discussion of the anatomical 

 and morphological characters of the genera, and a detailed 

 description of the anatomy of the leaves of seventy species 

 of Diospyros and of other fifty species belonging to the 

 remaining genera. Several complicated and ingenious tables 

 are given, intended to show the relationships of the species 

 of each genus to one another, the conclusions being based on 

 the work of Hiern and the anatomists previously mentioned. 

 Analytical tables for the genera and species are constructed 

 on the sex characters of the flowers as determined by Hiern, 

 together with the pericyclic or sub-epidermal origin of the 

 phellogen in the stem. Parmentier believes that the genus 

 Diospyros is characterized by a sub-epidermal phellogen in 

 the stem, and on this ground, since D. oppositifolia, Thw., 

 and D. suberifolia, Dene., have a pericyclic phellogen, he 

 transfers them to the genus Euclea. 



Such a position is untenable, and it is unwise to lay down 

 such rigid classifications from observations on only 40 per 

 cent, of the species of Diospyros ; furthermore, the sex of 

 one of the species, viz., D. jopppsitifolia. Thiv., was not then 

 known, and though it was regarded as being dioecious, I 

 have since been able to prove that it is monoecious onlyl 

 The classification put forward is further weakened by the 

 discoveries regarding the true nature of the sex of Diospyros, 

 and the behaviour of the phellogen in the pericycle and 

 cortex of the primary axis. 



The detailed accounts of the parts of the leaf and the 

 grouping of species of Diospyros according to the subcentric 

 or bifacial mesophyll, the immersion or projection of the 

 median and lateral traces, and similar leading characters are 

 ^particularly instructive, though we cannot but regard the 

 tables of affinity, such as that on pages 56-57, as being 

 premature, seeing that our knowledge of the whole order was 

 then, and still is, meagre and unreliable. 



We have seen that from 1873 the main work has been on 

 the anatomy of the stem and leaves and the origin layer of 



