RECREATIVE NATURAL HISTORY. 



points of OB, o c, be joined, then will D B o r be a 

 parallelogram. For by the last proportion, since E, o are the 

 at. 'Ml.- points of AO, oo, the side* of the triangle AGO, BO U 

 parallel to A o ; and since D, r are the middlo i><>int of the Bides 

 A B, B o of the triangle ABO, there- 

 fore D r is parallel to A o ; bat B o 

 is parallel to A o, hence, by Eno. L 

 80, a ia parallel to D r. Again, 

 because D, are the middle points 

 of B A, A o, the sides of the triangle 

 BAC, therefore D E is parall'-l t . 

 BC ; and because r,o arc the middle 

 points of the sides B o, o c of the 

 triangle B o c, therefore K o is pa- 

 rallel to B c, and D B is parallel to 

 B c. Therefore, by Eno. I. 30, D B 

 is parallel to r a ; hence, since the 



opposite sides of the four-sided figure D x o v have been proved 

 parallel, it is a parallelogram. Q. E. D. 



PROPOSITION XLIII. If in the last proposition H, K (Fig. 42) 

 be the middle points of o A, B c respectively, the six-sided figure 

 D F K o B H shall be equal to one-half the triangle ABC. For, 

 by Proposition XLI., since F, o, K are the middle points of the 

 sides of the triangle o B c, the triangles o F o, F o K are each 

 equal to one-fourth of the triangle o B c. Therefore the whole 

 parallelogram o F K o is equal to one-half the triangle O B c ; 

 similarly, the parallelogram o o E H is equal to one-half the 

 triangle OCA, and the parallelogram o H D F is equal to one- 

 half the triangle o A B ; hence by addition the whole hexagon 

 D F K a E H is half the triangle 

 ABC. Q. E. D. 



PROPOSITION XLIV. If D 

 (Fig. 43) be the middle point of 

 B c, the side of a triangle ABC, 

 and A D be joined, then, if D A 

 be equal to D B or D c, the angle 

 at A is a right angle. For since 

 D A = D B, therefore, by Euc. 1. 5, 

 angle DAB equals angle DBA; 

 again, since D A = D c, angle D A c equals angle D c A, therefore, 

 by addition, angles DAB and D A c are together equal to angles 

 DBA and D c A. But angles DAB and D A c make up whole angle 

 BAC; hence angle BAG is equal to the two angles ABC and 

 A c B. But the three angles together are equal to the right 

 angles (Euc. I. 32), hence BAC, the half of the whole, is equal 

 to one right angle. Q. E. D. 



With this proposition we conclude our "Exorcises in Euclid." 



RECREATIVE NATURAL HISTORY. 



THE COCOA-NUT PALM. 



IT would be difficult to find amongst the legion of priceless gifts 

 with which Nature has enriched the human race, one more mar- 

 vellous in its range of usefulness than the cocoa-nut palm (Coco* 

 nucifera). Not only are its numerous products capable of being 

 utilised in an almost endless number of ways, but the tree itself 

 may be viewed in the light of a pioneer amongst vegetable pro- 

 ductions, by whoso aid the first links of the great chain of plant- 

 life amongst the newly-formed islands of the southern and 

 eastern seas are established. In order to see how this great 

 work is accomplished, we must first direct our attention to 

 one of the so-called reef -ponds of the South Seas. The irregular 

 ring of coral reef that encircles the central mirror-like pool in 

 all but one narrow space which affords access to the interior, has 

 been formed by the coral insect, which is always at work, rear- 

 ing his structures directly upwards until the surface is gained. 

 But the action of the waves often breaks down part of his work, 

 and the broken fragments of tide and tempest help to fill up the 

 cavities between the surrounding rocks, and bring the general 

 mass nearer the true sea-level. Shingle, sand, dead and empty 

 shells, and sea-weed all help in filling up the deep rock pools, 

 and form lurking-places for crustaceans who feed on the dead 

 and stranded fish, whose bones, with the cast-off carapaces of 

 the crabs, and the thorn-covered crust of echini, gradually but 

 certainly tend to fill up and make the rugged surface level. 

 Sea-fowl, wearied by their long and devious flights, now take 

 their rest on the newly-formed deposits, and add recent guano, 

 feathers, and dead birds to the increasing store. At length 



the ouooa-nnt, driven before the fate fr 



-. : 



comes floating along in its dense, tough, boat like 

 m the breaker* dash in on the newly .formed fttrand, it is ou4 

 high and dry amongst the very elements best sotted to tu 

 development and growth. Warmed by a tropical son, the germ 

 rapidly shoots forth. The fibre* of to* old bonk b*lp to alter 

 the new rootlets, until the yuoag palm, in it* pride of life and 

 vigour, shoots boldly op heavenwards, bean its crops of rich 

 and massive treasures, which, falling oa virgin Hid fertile sofl, 

 in their torn shoot up, fructify, and in torn die, to famish 

 vegetable elements to the earth by their decay. As the seasons 

 pass on, and tropical storms sweep across islands aad con- 

 tinents, land birds, driven from their homes by sfases of weather, 

 take refuge in our cocoa-nut grove, and bring with them ia 

 their crops the undigested seeds of the trees and plants indi- 

 genous to the hind they have strayed from. These, falling to 

 earth, grow, blossom, seed, and pass away, to be replaced by a 

 crowd of descendant*. Other visitors, bird and insect, follow 

 in due course, until man, dincovering the new land, claims it as 

 his own, rears his hut amungut the cocoa groves, and avails 

 himself of the results of Nature's unerring handiwork. 



Thus without labour, or the aid of the appliances of semi- 

 civilised life, savage man can find the means of subsistence 

 prepared to his hand. The cocoa-nut palm, however, like most 

 other valuable vegetable productions, has had a great deal of 

 attention paid to its cultivation and management. Few trees 

 of this description thrive well at a greater height above the sea 

 than 600 feet. The range of the cocoa palm is very extensive, as 

 it is found in Africa, the East and West Indies, South America, 

 and throughout the counties 1 ; clusters of islands which dot the 

 southern seas. Little or nothing U known in this country of 

 the different varieties of nuts produced in different regions; 

 but by the native cocoa-nut growers they are as well understood 

 as distinctive differences between apples and pears grown in oar 

 own gardens. In the inland of Tahiti (in the Society group), the 

 natives describe six kinds of cocoa-nuts, all of which are known 

 by some particular name. In the island of Ceylon four descrip- 

 tions of nuts are found, each kind possessing some peculiar and 

 well-marked quality. The tembili, for example, is an extremely 

 attractive, rich-looking nut ; it is of oval form, and of a 

 warm orange tint. Great numbers of tembili trees are usually 

 cultivated by Buddhist priests in the vicinity of their temples, 

 in. order that a number of acceptable offerings to place at 

 the disposal of the charitably disposed traveller may be always 

 at hand when wanted. There are several sub-varieties of the 

 tembili. Then there is the edible-skinned cocoa-nut, or wanton; 

 this is of brighter colour than that just described, and is re- 

 markable for the peculiar character of its husk. When tho 

 outer skin is removed, the inner rind quickly changes to a light- 

 red colour, when it is eaten without further preparation. This 

 nut is slightly heart-shaped. Another description is remarkable 

 for its smallness and round form ; whilst the most common is 

 the ordinary commercial cocoa-nut. 



Most of our readers who are in tho habit of visiting museums 

 or collections of curiosities, will not have failed to observe 

 specimens of a large, dark-coloured and double-shelled cocoa- 

 nut ; the two cavities or bodies being held together by a sort 

 of band, much as the Siamese Twins are united, only that in the 

 case of the nuts the union consists merely of shell, instead of 

 vital tissues. The origin of those double or sea coeoa-wvto, as 

 they have been called, long remained enveloped in a cloud of 

 dense obscurity, and all that was known of them was, that 

 after the prevalence of certain winds, they were to be found 

 stranded on the coast* of the Maldive Islands, and that fortu- 

 nate mariners sometimes discovered them floating on the waves 

 far at sea. Such nuts as reached the shore were considered the 

 sacred property of royalty, and any attempt at concealment 

 on the part of the discoverer was punished by immediate death. 



Extraordinary virtues were in early days attributed to these 

 double nuts. Their contents were considered unfailing antidotes 

 to the most virulent poisons, whilst the fast-waning powers of 

 the aged were supposed to be completely restored by a medicine 

 prepared from the sea-nut. The value attached in past times 

 to this production appears in these enlightened days perfectly 

 fabulous. We are informed that the Emperor Rudolph IL, 

 when in treaty for one of these much-coveted rarities, caused 

 4,000 florins to be offered, but that sum being considered by the 

 vendors insufficient, it was refused. We find 



