40 Timehri, 
this highly important and intensely interesting question. Perhaps the most 
recent is the method patented by Mr. W.L. Spence, in July, 1910, whose aim has 
been to reduce the cost of tapping operations by lessening the number of times 
necessaly for collecting the latex, in addition to various other advantages. 
By this method constriction of the trunk is obtained by a band of rubber, 
rope, or steel spring, above the cut, by which ingenious means the latex is 
literally forced out. , 
In British Guiana, we are told, an all-important question is the hour at which 
tapping operations are carried out. From personal experience it can be stated that 
Sapium Jenmanz yields latex at almost any hour of the day, but it is said that 
there is no flow obtained from H. brasiliensis when the sun is high in the heavens, 
and that, consequently, it is necessary to tap during the very early hours of the 
morning. This is certainly a dismayed account, but one has to remember 
that the trees which are responsible for this statement are quite ten or twelve 
years old and have never up to this time been touched. The fact has already 
been referred to that trees which have never been tapped until they have reached 
a respectable age and size, often do not compare favourably, as regards the flow 
of latex, with trees which have been systematically and carefully tapped from 
the age of from five to six years. 
Possibly this may, in some way, account for the rather erratic behaviour of 
the latex of these trees. 
The question is one which must give rise to anxiety, for the difficulties in the 
way of turning out gangs at a sufficiently early hour in the morning, so as to be 
in the rubber fields and at work, soon after 5 a.m., are distinctly real. 
With regard to the question of mixed cultivation, the subject is one, the 
importance of which demands a special paper for itself. Cacao has been recom- 
mended both as a catch crop and a permanent cultivation in rubber areas, 
whilst limes also appear to have been tried with some amount of success, as a 
permanent cultivation. 
No local paper on rubber can be closed without reference to Macwarri- 
balli (Forsteronia near gracilis), which genus of the Apocynaceae was dis- 
covered by the late Mr. G. 8. Jenman, and which appears to yield good 
commercial rubber. It has been found up the Demerara river and in the North 
Western District. Probably in the future we shall hear more of this interesting 
plant, through the efforts of the Forestry Officer. 
Growers of Para, and other rubber trees, would be well-advised to exercise 
the greatest caution in clearing forest lands for rubber planting. Strong and 
sturdy wind belts should not only be left, but also belts of trees some 100 feet in 
width, at regular intervals, throughout the cultivation, so as to retain forest 
conditions as much as lies in one’s power. It is extraordinary how rapidly 
changes appear on lands which have been entirely denuded of forest growth. 
Every effort, also, must be made to keep up the supply of humus, a by no 
means easily obtained condition. 
For mulching purposes, nothing could be found better than rice straw, huge 
quantities of which can be obtained at the harvesting of this crop. 
