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AMERICAN FORESTRY 



A NESTING-TREE OF THE SOCIABLE GROSBEAK 



'THIS tree in itself is not wonderful, but curious and interest- 

 ing in its transformation ; the tree is a member of the mimosa 

 family, a leguminous tree common in South Africa. It is the 

 tree usually chosen by the Sociable Grosbeak for a breeding 

 colony of his kin-folk. The grosbeak is a small bird represented 

 by the cardinal bird and the bullfinch; it is also in the sub- family 

 of the weaver birds. This tree, therefore, is interesting because 

 it supports a nidamental city which has transformed the entire 

 spray of the tree into a bird tenement. 



The birds continue to build in the same tree from year to 

 year and with the increase of the families there must be a 

 corresponding increase in nest-making, until the tree falls from 

 its burden of nests. The building material is fine grass. The 

 entrances are below and these entrances are not to single nests, 



but to streets along both sides of which are nests about two 

 inches apart. The work required for such an accumulation of 

 material, straw by straw, is incredible, almost rivaling that of 

 King Cheops and his great pyramid. Man is a social being; many- 

 birds and animals are also gregarious. There are still aboriginal 

 tribes who build their homes in the trees, as the Vedas of 

 Ceylon. Home-making in the trees, on the part of man, may 

 be an inherited instinct from our Simian ancestry. These Nest- 

 ing trees of the Sociable Grosbeak often represent in the single 

 tree from eight hundred to one thousand birds. In the museum 

 of Capetown an entire tree, similar to that shown in the illus- 

 tration, may be seen. Surely this little finch we call the Sociable 

 Grosbeak exemplified the advantage of co-operative labor 

 thousands of years before it has been widely adopted by man. 



AT SNAKES ARE THESE ROOTS OF THE RUBBER TREE 



Rubber trees of different varieties and yielding various grades of rubber are found in most tropical countries. The annual yield from young 

 trees is from two to three pounds, while from the large old trees it may exceed forty pounds. 



THE RUBBER TREE AND THEIR PRODUCT 



'T'HAT wonderfully useful tree-product familiarly known as 

 India rubber was first discovered during the second voyage of 

 Columbus to the New World, wherem it was recorded that the 

 natives in Haiti were found playing with balls of this amusingly 

 resilient substance, and on account of this quality it was called 

 elastic gwn. In 1770 one Priestly, a chemist, finding this gum 

 effective in rubbing out pencil marks gave it the name India 

 rubber. In Peru and Ecuador where certain species of the rub- 

 ber-tree are indigenous, both the tree and its product are called 

 Cahucha, or Caucho, hence the origin of the modernized term 

 Caoutchouc (Koo-chook), for the milky juice of the rubber 

 trees ; but this name is so unspellable and unpronounceable that 

 the more simple and euphonius word latex may be used. 



There are several species of trees and vines which yield this 

 valuable substance, latex, and which must not be confounded 

 with the vital nourishing sap of the tree. The latex exudes 



from sacs in the inner bark of the tree and chemically, is essen- 

 tially a hydrocarbon. It seems in no way necessary to the nourish- 

 ment of the tree, and its real function is not well understood. 

 This lactescent juice produces 20 per cent and upwards of 

 rubber. Of the several species of rubber producing trees and 

 vines, those producing what is commercially known as Para 

 rubber are the most widely cultivated, Para rubber being the 

 standard by which the different grades are rated in the markets 

 of the world. Para rubber is the product of a tree known as 

 Hevea Brazilicnsis, a native of the Amazon Valley. Another 

 rubber tree indigenous to Brazil yields what is known as Ceara 

 rubber; These two species of rubber trees are now well repre- 

 sented in the plantations of the East. Another species, Ficus 

 elastica (Fig elastic), yielding the rubber called "Rombong" in 

 the market, is a native of Assam. Ficus elastica is often culti- 

 vated as a garden and house plant in Europe and America, and 



