Chap. 38:] FACTS CONNECTED WITH LEAVES. ^77 



grassy colour, and has a smooth surface ; 55 while the veins, the 

 callous skin, and the articulations, lie upon the upper face, the 

 veins, making incisions in the parts beneath, like those to be 

 seen upon the human hand. The leaf of the olive is whiter 

 above, and not so smooth ; the same is the case, too, with that 

 of the ivy. The leaves of all trees turn 56 every day to- 

 wards the sun, the object being that the under side may be 

 warmed by its heat. The upper surface of them all has a 

 down upon it, in however small quantity it may be ; in some 

 countries this down is used as a kind of wool. 57 



CHAP. 37. THE CARE BESTOWED ON THE LEAVES OF THE PALM, 



AND THE USES TO WHICH THEY AB.E APPLIED. 



We have already said 58 that in the East strong ropes are 

 made of the leaves of the palm, and that they are improved by 

 lying in the water. Among ourselves, too, the leaves of the 

 palm are generally plucked immediately after harvest, the best 

 being those that have no divisions in them. These leaves are 

 left to dry under cover for four days, after which they are 

 spread out in the sun, and left out in the open air all night, 

 till they have become quite white and dry : after this they 

 are split before they are put to any use. 



CHAP. 38. — REMARKABLE FACTS CONNECTED WITH LEAYES. 



The broadest leaves are those of the fig, the vine, and the 

 plane ; while those of the myrtle, the pomegranate, and the 

 olive are narrow. The leaf of the pine and the cedar is fine 

 and resembles hair, while that of the holly and one variety of 

 the holm oak 59 is prickly — indeed, in the juniper, we find a 



55 These statements are quite conformahle with the fact. 



56 This statement is quite true, so far as the fact that the leaves have 

 not the- same position in the day-time as during the night : the changes of 

 position vary greatly, however, in the different kinds. It is generally thought 

 that an organic irritability is the cause of this phenomenon. 



57 This seems to be the meaning of " In aliis gentium lana est." He 

 alludes, probably, to cotton or silk : see B. vi. c. 20. Thunberg tells us that 

 at Roodesand, near the Cape of Good Hope, there grows so thick a down 

 ou the Buplevrum giganteum of Lamarck, that it is employed to imitate a 

 sort of white velvet, and is used for bonnets, gloves, stockings, &c. 



5 » B. xiii. c. 7. 



59 " Genere ilicum." It is not improbable that he here refers to the variety 



