Occasional Notes. 309 
are of purely negro habits. And it is very difficult to 
draw a line between these two classes. The second 
difficulty lies in the fact that to restrict Indians from 
cutting wood — and by wood,, in this colony, is virtually 
meant, greenheart — above a certain diameter is to force 
them to cut the small, immature greenheart which it is a 
matter of extreme importance to leave, to replace the 
forest. 
Sir Joseph Hooker on a new Botanical Genus from 
British Guiana. — The following letter received by Mr. 
JENMAN from Sir JOSEPH HOOKER is of considerable 
interest. It should be stated that — by a slight mistake — 
the writer wrongly attributes two of the species to which 
reference is made to me and refers only one to Mr. 
JENMAN ; whereas Mr. JENMAN really sent two, I only 
one ; though mine was the first. The letter is as fol- 
lows : — 
" I have just concluded the study and description of the most curious 
'* new genus about which you ask, and of which there are two species, 
'' both sent by Mr. im Thurn, and one by you also. One of them is 
" a published plant, appearing in Rudge's " Plantarum Guiana; 
" Rariorum Icones et De'scriptiones" as Mnasium sphcerocephalwm 
" Mnasium is. however, equivalent to Rapatea ; and, as a new generic 
" name for the Guiana plants must be found, I have called the genus 
" Thurnia, and the two species 
T. splimrocephala (the one with serrated leaves). 
T. Jenmanni. 
" The development of the seed in Thumia is most extraordinary, and 
" we much want fertile flowers in all stages of growth, in spirits, of 
" both species. We have only fertile (flowers) of T. splimrocephala and 
" only barren of T. Jcnmanni. Quite a small phial would hold enough 
" pieces of the heads for analysis. Please get them if you can when 
"you go on to the savannah I am figuring both ThurniaV 
