June 1908.] 



510 



Saps and Exudations. 



known some particulars of this most 

 useful plant. Showing how its plantation 

 should be made, how it should be treat- 

 ed, and the manner of extracting the 

 rubber. This is what we intend to do, 

 makirg use of other works already 

 issued, intending to add to them without 

 damaging their clearness. 



The Tree. 



The Manicoba (Manihot Glaziovii) be- 

 longs to the family of Euphorbiaccae, to 

 which also belong Hevea brasilierisis 

 which produces the excellent rubber of 

 the Amazon. 



It grows not only in the interior, but 

 also near the sea, and on mountain sides, 

 doing well iu the pastures ranging 

 between 15°C. and 32°C. [59°P. and 70°P] 

 that is all over Brazil. 



It is probable that its habitat covers a 

 great part of the country periodically 

 destroyed by drought, from the banks of 

 the river San Fran cisco to those of the 

 Parahyba. 



As to the condition of the soil in which 

 it vegetates, it seems that the Manicoba 

 requires little, doing better in clay 

 lightly mixed with sand. 



The resistance of the plant to extreme 

 drought, and at the same time its suit- 

 ability to well irrigated and fresh earth 

 cannot be explained. On dry table lands 

 of hard clay fine and luxuriant examples 

 of the Manicoba are raised. 



Only on the sandy earths of beaches 

 where the air is always damp the plant 

 will vegetate quickly. 



The hygrometrical state of the temper- 

 ature will make the plant commence in the 

 production of " latex," immediately after 

 the winter, in the months of May and 

 June. This flow of liquid, thin, and 

 without consistence, is easily taken in 

 " Flanders tin cans," in which it coagu- 

 lates within 4 to (3 hours. 



The amount which the dry season 

 advances, rarefies the milky secretion, 

 and from flowing it passes to dropping, 

 coagulating rapidly on coming in contact 

 with the atmosphere. 



The latex is a liquid of glutinous con- 

 sistency, made up of two elements, one 

 liquid hardly coloured, the other very 

 fine globules unequal, and of varying 

 colour, which swim in the liquid. The 

 circulation seems to be descending, and 

 is favourable to the nutritive moisture ; 

 as to the form of these milky vessels, 

 they are simple on ramified tubes, com- 

 pletely closed, of transparent Avails, and 

 without any appearance of punctuation 

 or of transversal lines. 



The latex which produces the rubber 

 is different to the sappy or nutritive 

 moisture of the plant, and unless there 

 be some means of invigorating the 

 latex, then the belief of the explorators 

 of the Seringuera, or the Manicoba, 

 that the extraction of the milk weakens 

 the tree is not unreasonable. The wood 

 of the Manicoba is spongy, light, white. 

 The Oupim (insect of Brazil) attacks the 

 wood as it does white pine. Giant trees 

 do not resist the undermining by the 

 Cupim for more than one year, and when 

 the first high wind comes they fall, 

 throwing sometimes to the ground the 

 shoots which take root and form new 

 growths, at other times in the falling 

 the seeds get scattered and quantities 

 of plants spring up. The tree of the 

 Manicoba attains a height of 30 feet, it 

 has a round shape, and its leaves are 

 similar to those of the Mamoa tree and 

 of an ashy green colour. 



Planting Manicoba. 

 The seed is hard, flat and smooth, 

 nearly the size of a matured coca cob, of 

 dark olive colour. Its hardness is extra- 

 ordinary, resisting very heavy compres- 

 sions, also its permeability to water, in 

 which it may remain for a long time 

 without putrefying or saturating. With- 

 out doubt because of this circumstance 

 some planters lay them in a bed of sand, 

 covering them with straw, thus parching 

 them superficially. The hard scab of 

 the seed dilates and splits, then on 

 transplanting it grows easily. 



This process is dangerous as it is liable 

 to expose the germ of the plant ; it is 

 preferable to make a plantation in a 

 nursery and transplant after, as is the 

 custom with coffee trees. 



Planting by cuttings does not offer any 

 real advantage aud can only be attempt- 

 ed with any result when the first rains 

 of the year are over. For besides 

 maiming the vigorous shoot of the mother 

 plaut, it is difficult for the cuttings to 

 take root, and even after they have 

 taken root, they resist but poorly any 

 variations of the summer on the hills, 

 but in damp districts, which are never 

 really wet, this system is perhaps better, 

 so as to hurry the development of the 

 plant, and consequently for its industrial 

 profit. In any case it does not do for an 

 extensive cultivation, 



When care is taken to choose the seeds, 

 avoiding those which float on the water, 

 the plant comes up robustly, looking 

 whilst young like "Ricinus" (Castor oil 

 plant) or "Manioca" (Cassava). 



During the first three or four weeks 

 it grows from 8 to 12 inches, going 

 ahead from then rapidly, attaining thre^ 



