May 1908.] 



417 



Saps and Exudations. 



breezes and where the soil, though fre- 

 quently swampy, is lighter in texture, 

 will probably suit the tree better. 



The seeds can be obtained from about 

 March to May, and the ripe ones can be 

 recognised by their red colour. On 

 account of their comparatively small 

 size they will only require a light cover- 

 ing of soil after sowing. The young 

 plants are also to be found springing up 

 in the neighbourhood of the trees, where 

 sufficient light is admitted into the 

 forest. They are very hardy and will 

 endure lifting and transportation well, if 

 the soil around their roots be disturbed 

 as little as possible and the roots are 

 kept damp. 



Another method of propagation which 

 has proved very successful wheu tried on 

 young trees growing in the nursery is 

 by "ringing" the younger branches in 

 the same way that rose trees are often 

 propagated. 



As the fully grown tree reaches a huge 

 size, I should not recommend planting 

 closer than 20 feet in both directions. 

 If the trees are planted on land already 

 cleared, some light shade in the form of 

 plantains or some tall-growing banana 

 will probably be beneficial, and the land 

 between can be used for growing other 

 crops. 



Where, however, it is desired to plant 

 S. Jenmani in uncleared forest land, an 

 experienced forester, who has lately been 

 visiting British Guiana did not advise 

 clearing the land for the purpose, as it 

 would soon be followed by a growth of 

 weeds and bush which it would be ex- 

 pensive to keep in check. He recom- 

 mended the clearing of narrow, straight 

 lines in the forest running parallel with 

 each other and at approximately regular 

 distances apart, e.g., 20—25 feet, and 

 planting the trees at uniform distances 

 along these. The shade would keep 

 down the growth of bush and weeds over 

 the greater part fof the land and would 

 assist the growth of the Sapiums. A.s 

 the latter increased in size, the forest 

 trees would have to be cut down to make 

 room for them. For these same reasons 

 he considered that it would be cheaper 

 to plant Sapiums in the uncleared forest 

 according to the method advocated 

 above than to plant them on land al- 

 ready totally or partially cleared. 



At the present time only one planter 

 in the colony has been putting in Sapi- 

 ums to any considerable extent. This 

 man is the owner of a large grant on the 

 Aruka River, and he has planted over 

 15,000 trees on his property, which he 

 reports are making good growth. 

 Several of his neighbours are now copy- 



ing his example and most of the culti- 

 vators along this river have each their 

 own little rubber cultivation. 



Hevea. 



The Heveas can be readily distin- 

 guished from the Sapiums by the leaves 

 being compound, instead of simple as in 

 the latter, i.e., each leaf consists of three 

 distinct leaflets, borne at the end of a 

 long stalk and each leaflet is provided 

 with a short stalk of its own. 



All the Heveas are forest trees, exud- 

 ing a milky juice when any part of the 

 tree is wounded or cut, On the upper 

 surface of the main leaf -stalk, at its apex 

 where the three short stalks of the leaf- 

 lets, arise, are usually to be found a few 

 rounded glands, appearing as small 

 depressions with raised margins. Their 

 number varies in the different species 

 from two or three to as many as four or 

 five, but sometimes they are wanting. 

 Their presence and number is of some 

 value in discriminating between the 

 different species. 



The flowers of Hevea are arranged in 

 branched panicles and are small and 

 green. As in Sapium they are destitute 

 of petals, and there are distinct male and 

 female flowers, the latter being rather 

 larger than the former and mostly borne 

 at the ends of the branches of the in- 

 florescence. The calyx of each flower 

 has five teeth or lobes. 



The male flowers contain five to ten 

 stamens arranged in one or two circles 

 round a central column. The female 

 flowers possess a more or less egg-shaped 

 ovary with three divisions, each of 

 which contains one ovule. When the 

 ovary ripens it forms a large woody 

 capsule, which at maturity splits open 

 with a report into three valves, scatter- 

 ing the seeds to some distance. 



The seeds are large and rounded and 

 somewhat oblong in shape. In Hevea 

 brasiliensis they measure an inch across 

 the largest diameter. The seed-coat or 

 testa is smooth and rather thin ; it is 

 usually of a gray colour mottled and 

 streaked with irregular brown markings. 

 The seeds lose their power of germin- 

 ation very quickly, but they may be pre- 

 served for as long as two months, packed 

 in charcoal which has been slightly 

 damped. When sown the seeds germin- 

 ate in a week or ten days' time and the 

 young plants are of rapid growth. 



The Heveas which include about 

 twenty species are all found in the tro- 

 pical regions of South America. The 

 only species hitherto recorded from 

 British Guiana are Hevea spruceana, 

 Muell. Arg.; H. pauciflora, Muell. Arg.; 



